Sources on Wasting Seed

B6:4, Bereishis   הַנְּפִלִים הָיוּ בָאָרֶץ, בַּיָּמִים הָהֵם, וְגַם אַחֲרֵי-כֵן אֲשֶׁר יָבֹאוּ בְּנֵי הָאֱלֹהִים אֶל-בְּנוֹת הָאָדָם, וְיָלְדוּ לָהֶם:  הֵמָּה הַגִּבֹּרִים אֲשֶׁר מֵעוֹלָם, אַנְשֵׁי הַשֵּׁם

B38:7-10, Va’yayshev                                                                                     וַיְהִי, עֵר בְּכוֹר יְהוּדָה--רַע, בְּעֵינֵי יְהוָה; וַיְמִתֵהוּ, יְהוָה

וַיֹּאמֶר יְהוּדָה לְאוֹנָן, בֹּא אֶל-אֵשֶׁת אָחִיךָ וְיַבֵּם אֹתָהּ; וְהָקֵם זֶרַע, לְאָחִיךָ

וַיֵּדַע אוֹנָן, כִּי לֹּא לוֹ יִהְיֶה הַזָּרַע; וְהָיָה אִם-בָּא אֶל-אֵשֶׁת אָחִיו, וְשִׁחֵת אַרְצָה, לְבִלְתִּי נְתָן-זֶרַע, לְאָחִיו

וַיֵּרַע בְּעֵינֵי יְהוָה, אֲשֶׁר עָשָׂה; וַיָּמֶת, גַּם-אֹתוֹ 

Yevamos 34b  Er sinned by pulling out at the end of having relations with his wife Tamar, and not ejaculating inside her. Onan sinned by doing the same thing, although they had different reasons for doing it. Er didn’t want her to get pregnant so that she would maintain her figure, and Onan didn’t want her to get pregnant because he knew that the child wouldn’t really be his.

Nidda 13a-b  Whoever wastes seed deserves death. Whoever willfully causes an erection should be placed in nedooi.

Yevamos 76a

Eruvin 18b

Brachos 13b and Nidda14a

Nedarim 35b

Zohar (Bereishis)  For many were the evil of man... they committed every possible act of evil, however their fate was not sealed until they threw their blood down on the floor - until they spilled their seed on the ground.

Zohar (Va’yayshev)  Spilling seed is more severe then all sins, since he defiles his soul in this world and the world to come and he does not see the glory of the shichenah.

Zohar (II:214b, Vaya’khel)  The sin of spilling seed is more severe than any other sin.

Zohar (Zohar I:60a, Noach and I:219b, Vayechi )  There is no teshuvah for the sin of spilling the seed in vain.

Zohar (I:59b)  Who is a tzaddik? He who guards the bris. We learn this from Yosef, who received the title of Yosef HaTzaddik because he observed the bris.

Zohar (90a)  `He shall not profane his seed and his people.  Whoever discharges his semen without purpose will never be allowed to behold the divine Presence," and he is called evil. This isn’t the case, however, if a man's wife doesn’t conceive; still, a man should pray that Hashem should provide him a fitting vessel so that his seed shouldn’t be spoilt. For he who discharges his seed into a vessel that isn’t fitting spoils his seed.

Medrish Hagdol (Vayeshev)  R’ Yochanan spoke up and said all those who waste seed are punishable by death. Rav Ami said it is as if he sheds blood. Rav Ashi says it is as if he worships strange deities. Rav Acha bar Yashya said whoever wastes seed equates himself to an animal. Just like an animal does not care what it does, so to this person randomly commits this sin. Just like an animal is set aside to be slaughtered and does not receive life in the future world so to this person stands to die and does not live in the future world.

Tanah Divi R’ Yishmoel  Why does S20:12 say lo sinuf, which is in the plural form? Because it comes to include those who spill seed

Bereishis Rabba   When the people heard about the flood, they became even more immoral and they would spill their seed on the ground in public with no shame.

Rashi (B38:7 “Bad in the eyes of Hashem”)  Like the sin of Onan, who would spill his seed.

Rashi (Yechezkel 23:37 “And also their children”)  This was counted as murder, meaning they wasted seed and didn’t do teshuva.

Rashi (Shabbos 41)  The flaw of the dor ha’mabul was that they would waste their seed.

Rambam (Hilchos Issurei Biah 21:18)  It’s uhser to waste seed. Those that do it place themselves in nidooi. Wasting seed is equivalent to killing someone.

Ramban (cited in Maggid Mishna, Hilchos Issurei Biah 21:18)  If someone wastes seed, bais din is commanded to place him in cherem.

Rabbeinu Tam (Tosfos Nidda 13b)  When the Gemara says that one who willfully causes erection should be put in excommunication, it means that bais din gives him needooi.

Rabbeinu Yona (Sefer HaYirah)  One should be careful not to waste seed.

Tur (E”H 23)  It’s uhser to waste seed. Those that do it violate a serious isser, and they also place themselves in nidooi. Wasting seed is equivalent to killing someone.

Shulchan Uruch (E”H 23:1)  Uhser l’hotzee shichvas zerah l’vatala, v’uhvone zeh chamur m’kol aveiros she’baTorah.

Be’er Hagola  The source for this is the Zohar on parshas va’yayshev.

Shulchan Uruch (E”H 23:2)  Those who are promiscuous with their hand and ejaculate, not only is it an isser gadol, but they sit in needooi, and about them the pasuk says “your hands are full of blood” (Yishaya 1:15) and it’s as if they murdered.

Kitzur Shulchan Uruch (151)  It’s uhser to waste seed, and it’s the most severe of all the issurim in the Torah. If a person does this, it’s as if he killed a person, based on Yishaya 1:15, “And when ye spread forth your hands, I will hide My eyes from you; when you daven many times, I will not hear; your hands are full of blood.” And Yishaya 59:3 says, “For your hands are defiled with blood, and your fingers with iniquity; your lips have spoken lies, your tongue muttered wickedness.”

Radvaz (shut 161:5)  He will be placed in excommunication, like all those who spill their seed.

Radvaz (shut 596:3)   Those who destroy their seed bring a flood to the world.

Rav Yaakov Emden (Mishpachas Sofrim)(shut Shailat Yaavetz 43)  Hashchasas zerah isn't a very severe isser.

Me’am Loez (B38) cites the Shluh: It’s uhser to waste even bread crumbs, kal v’chomer if someone wastes something as precious as sperm.  There are several ways to do teshuva:  1) Shed tears during vidooi, 2) Prevent others from sinning, 3) Be humble and slow to anger, 4) Don’t speak in shul at all, 5) Be a sandik, 6) Say brich shmay when the Torah is taken out of the uhron on Shabbos and Yom Tov, 7) Give tzidaka during shacharis, 8) Do the mitzvah of oneg Shabbos, 9) Have a set learning every night before going to sleep - no matter how little, 10) Sweat with effort while doing a mitzvah such as digging a grave, baking matzos, or building a succah.   Try to do these 10 things for the rest of your life.  [English footnote says it’s also good to go to the mikva and recite the tikun kluli.]  If this activity was considered sinful in those days, even before the Torah was given, it’s considered even more sinful now. 

This sin causes three negative effects: 1) It lengthens the galus, as we learn from B15:13, “your seed will be a foreigner”, 2) It causes plague and other catastrophes, 3) It can cause your children to go astray or even die young. 

A nocturnal emission is considered willful if you had done one of the following things: 1) Staring at women and speaking with them, 2) Speaking with dirty language, saying lashon hara, or lying, 3) Saying brachos l’vatalos, 4) Teaching Torah to non-Jews (the isser is learned out from T147:19-20), 5) Making vows and not keeping them, 6) Eating and drinking too much, 7) Sleeping alone in a room, 8) Watching animals mate, 9) Gazing at idolatrous figures, 10) Being depressed (you should always be satisfied with what Hashem gave you), 11) Listening to uhser speech, 12) Sleeping with unclean objects near your bed such as shoes, socks, and pants - even if they’re new.

Pnei Yehoshua (shut E”H 2:44)  The isser of hashchasas zerah l'vatala isn’t included in gilui arayos or lo sirtzach. Even though Chazal say that it’s if he committed murder, they meant to emphasize that the sin was as great as sin of murder. And, when they compare it to isser of gilui arayos, they mean that this was at a dirabunun level. I base this idea on the Rambam (Issurei Biah 21:18) and Rabbeinu Tam (Tosfos, Nidda 13b). Rambam discusses this isser and doesn’t say that a violator gets malkus, which is what he says by several other acts which are discussed there. Also, he doesn’t even say that the violator is given malkus mardus; he just says that the person is excommunicated (needooi). Based on Rabbeinu Tam, if this was an isser dioraisa, why should the Gemara need to tell us that he gets needooi? Even one who is ovare an isser dirabunun gets needooi? So it must be an isser dirabunun.
Ramak (Tomar Devorah 8)  One has to be extremely careful with his bris... He should never cause an improper erection... Be very careful not to damage the attribute of yesod.

Rav Chaim Vital (Shaarei Kedusha 2:8)  More severe then all sins is one who spills seed, for he spills the blood of his kids for all eternity. In addition all sins can be rectified, but this one has no rectification. Wasting seed is more severe then manslaughter, for here he is spilling his own blood and the blood of his children. In the Zohar parshas vyache it says all evil people can repent except those that commit this sin. In addition a person under the age of mitzvot is not held accountable for his sins except this one, for Er and Onun were underage and got punished. In addition the generation of the flood who were wiped off the face of the earth was only for this sin.

Reishis Chuchma (Shaar HaKedusha 17) discusses the Zohar’s statement about spilling seed and teshuva.

Tanya (Iggeres HaTeshuva 4) discusses the Zohar’s statement about spilling seed and teshuva.

Chida (Ahavas HaKodesh, Tziporen Shamir, 7:101)  He who desires to be saved from the sin of spilling his seeds in vain should not contaminate the bris of his mouth. He should be particular in guarding it from sicha betela and lashon hara, because the tongue and the procreative organ go together, meaning he who damages with his tongue will most certainly stumble with his organ

Kitzur Shulchan Uruch says the same as the Chida, and he adds that in the few minutes before going to sleep, you should learn Torah, maybe the first four prakim of Tehillim, and you shouldn’t sleep alone in a room.

Kaf HaChaim (240)  From all the sins in the Torah, there is none that create demons like one who spills seed. All souls who were to be his children now intermingle with the sitra achara. He turns kedusha into tumah, tov into ra.

Pelah Yoetz (7)  There is a type of znus that is quite common amongst the young people - they waste their seed. This comes from their ignorance of how damaging this act is. It’s an obligation to warn everyone young and old, let them know the severity of these issues until they tremble from fear. Every city should appoint men to watch and teach the people to stay away from this terrible sin.

Chai Adam (Kitzur Sefer Charadim)  “Lo Sinuf” teaches that one shouldn’t spill seed.

Shavet Musar (27)  When a person spills seed many impure forces attach themselves to the hairs of that region, from there are created evil spirits. They are the ones that are called ‘painful afflictions of man’. After he dies they do not leave him since they are his sons, there is no suffering bigger then this.

Shlah (100)  Hashem doesn’t answer the tefillos of a person who spills his seed.

Kav Hayoshar (68)  A person who spills his seed loses his ability to understand Torah.

Maharil (Shut 4)  Spilling seed destroys the world, it is counted as if he kills someone. This is referred to in the pasuk “one who slaughters his kids”.

Yavetz shut (43:1)  He gives power to the forces of evil and weakens the tribunal on high as is known to those wise of the truth, the masters of kabbalah.

Rav Poalim (shut 2:3)  Spilling seed is totally uhser. There’s never a time when it is permitted. A person who spills seed creates spirits of destruction.
Sredei Aish  There are opinions that spilling seed is an isser dioraisa.

Toras Chesed (Rabbi Shneur Zalman Pradkin, d. 1902, shut 2:33)  It's a machlokes Rishonim whether hashchasas zereh is an isser dioraisa or dirabunun. Tosfos (Sanhedrin 59b) seems to hold that it's dioraisa. Ramban and Meshivas Nefesh seem to hold that it's dirabunun (see Otzar HaPoskim 83a).
Iggros Moshe (E”H 3:14)  Hashchasas zera livatala is an isser dioraisa and the punishment is misa be’day shamayim, as Rebbi Yochanan says in Niddah 13a. It’s such a terrible aveira that the Shulchan Uruch (E”H 23:1) says that it’s the most severe of all the issurim dioraisa. And even though this isn’t to be taken literally, since having relations with a married woman or a nidda are very severe sins as stated by the Bais Shmuel, nevertheless the Shulchan Uruch wouldn’t have used such strong language if hashchasas zerah was only an isser dirabunun. Kesubos 45a says that Rebbi Pinchas ben Yair derived the isser of inappropriate thoughts, from the pasuk “You shall guard against anything evil” (v’nishmarta), explaining that this was so that he wouldn’t have a nocturnal emission. And Tosfos (Avodah Zara 20b) says that this should be considered pashut pshat of the pasuk (which would give the isser the status of dioraisa). Certainly then, the act of hashchasas zerah is included in v’nishmarta. The fact that it isn’t found in the Rambam's list of lavin doesn’t prove that it’s not an isser dioraisa, because there are many issurim dioraisa which aren’t included in that list. Perhaps this is because the Torah only says that it’s punishable by death without deliberately saying that it’s uhser (the 365 lavin listed by the Rambam each have two separate psukim in the Torah, one saying that it’s uhser, and the other saying the punishment). The lav of v’nishmarta includes other uhser acts in addition to inappropriate thoughts, and therefore the Rambam didn’t wish to list it as a separate lav. Ramban did count it as a separate lav (also see Iggros Moshe E”H 1:70).

Ezer MiKodesh (E”H 23)  Wasting seed is an isser dirabunun.

Chavos Yair (31) and others hold that abortion is a retroactive violation of wasting seed.