Clarifying the Sin of Onan

When talking about the reproductive health (RH) bill, barrier contraception (e.g. condoms, cervical caps), masturbation, and the withdrawal method, the sin of Onan is sometimes linked to the issue by anti-RH people, especially by anti-RH Catholics. They say that barrier contraception, masturbation, and the withdrawal method are connected to the sin Onan committed. 

In this post, we are going to clarify what really is the sin that Onan committed.

What happened to Er, brother of Onan, and his wife?

Judah and Tamar

According to the first book of the Torah (or the Pentateuch), which is the book of Genesis, Er is Judah's firstborn. (see Gn. 38:2-3, Gn. 38:6, and Gn. 38:7)  Who did Judah, Er's father, took as Er's wife?

"And Judah took a wife for Er his firstborn, whose name was Tamar." - Genesis 38:6 (KJV)

From that verse, we can conclude that Er had a wife, which is Tamar. Now, going back to our question, what actually happened to Er? What happened to him after being married to Tamar? This is what the Bible tells us.

"But Er, Judah’s firstborn, was wicked in the sight of the Lord, and the Lord killed him." - Genesis 38:7 (NKJV)

Er, because of being wicked, was killed by God, leaving Tamar a widow.

Who is Onan?

According to the Bible, Onan is the second son of Judah, next to Er. The third son of Judah is Shelah.

"And Judah saw there a daughter of a certain Canaanite whose name was Shua, and he married her and went in to her. So she conceived and bore a son, and he called his name Er. She conceived again and bore a son, and she called his name Onan. And she conceived yet again and bore a son, and called his name Shelah. He was at Chezib when she bore him." - Genesis 38:3-5 (NKJV)

As Er's younger brother, what must Onan do in accordance with the levirate law?

Raising up a Torah

As prescribed by the levirate law, Onan must take Tamar, Onan's widow, as his wife and perform the  duty of a husband's brother to her.

"If brothers dwell together, and one of them dies and has no son, the widow of the dead man shall not be married to a stranger outside the family; her husband’s brother shall go in to her, take her as his wife, and perform the duty of a husband’s brother to her. And it shall be that the firstborn son which she bears will succeed to the name of his dead brother, that his name may not be blotted out of Israel." - Deuteronomy 25:2-6 (NKJV)

Take note that Onan will not just take Tamar as his wife. He will also fulfill the duty of a husband's brother to her. One of the duties duly assigned to him as a younger brother of Er is to have a child with Tamar so that Er will have descendants. Take note that the child will not be considered Onan's since it will be considered Er's.

What did Onan do?

Onan was commanded by his father, Judah, to have sex with Tamar so that they could have a child who will be considered Er's descendant.

"Then Judah said to Er's brother Onan, Go and sleep with your brother's widow. Fulfill your obligation to her as her husband's brother, so that your brother may have descendants." - Genesis 38:8 (GNT) 

Take note that he needs to make Tamar pregnant so that Er may have descendants. (The child would not belong to him. It would belong to Er.) But what did Onan do?

"But Onan knew that the children would not belong to him, so when he had intercourse with his brother's widow, he let the semen spill on the ground, so that there would be no children for his brother." - Genesis 38:9 (GNT)

Onan knew that the children would not be considered his. That's why when he had sexual intercourse Tamar, Er's widow, he let the semen spill on the ground. By letting the semen spill on the ground, he wasn't able to make Tamar pregnant. Therefore, he wasn't able to fulfill his duty as the brother of Tamar's husband. He wasn't able to give Er children that would be considered his descendants. He refused to give Er descendants. He violated the levirate law. Because of that, what did God do to Onan?

"What he did displeased the Lord, and the Lord killed him also." - Genesis 38:10 (GNT)

By not giving Er descendants, Onan displeased the Lord. As a result, the Lord killed him also.

Is Onan's sin masturbation or withdrawal?

No. Masturbation or withdrawal is not the sin Onan committed though that did occur. Just like what I said, the sin Onan committed is refusing to give Er descendants, violating the levirate law.

By the way, there are other things that Onan can do which will also violate the levirate law like going to a far away place like Egypt to get away from Tamar. That would also make the Lord kill him.