Genesis 38:4

And she conceived again, and bare a son; and she called his name Onan.

The verse records the birth of Onan and his being named Onan. It belongs to the account of the sin of Judah and of his family. That account exposes sin so that it may be shunned rather than excused or made appealing, and it points to God's love, mercy, and power as its remedy.

The chapter stands among the sad fruits of Jacob's mistakes in having more than one wife, including jealousy between wives and families, low moral standards, and crime. As a loving but unwise father he lavished too little affection on his other sons compared with Joseph, the petted child of his old age by his favorite wife. This unwisdom developed hatred in Joseph's brethren that led them first to attempt to kill him and then to sell him as a slave into Egypt. The sorry incidents of Genesis 38 are not necessary to the narrative, while Genesis 37 and 39 onward show how God overrules human wrath, ambitions, and jealousies to praise Him and works out His providence for the true and faithful in the story of Joseph.

The history of Joseph to which the verse belongs proves that whatever God has intended a person for, He can be safely trusted to bring them to it even by a roundabout way. Principles of integrity and purity developed in Joseph, passed through two years of innocent imprisonment as needed discipline, led to God calling him to the throne of Egypt and to his brethren coming unconsciously to bow humbly before him in fulfillment of the dreams that had aroused their envy. The account shows the Lord's displeasure falling on a man who shirked the duty of a go'el. Tamar's actions were a strategy to obtain rights secured by law and custom after Judah fraudulently deprived her of them, the sons born from the union were counted as legitimate, and one was included in the ancestry of Jesus.

The verse belongs to the record of the human line from which Christ sprang as to His human nature, showing an ancestry that would tend to concentrate in Him all the weaknesses of humanity, since Pharez, an ancestor of Christ, was born to Tamar who was regarded as a harlot. This proves Christ took flesh not of a sinless being but of sinful man with all the weaknesses, sinful tendencies, and greater subjection to infirmities of the deteriorated race. That degraded ancestry was a necessary part of redemption so death could have power over Him through imputed iniquity and so He could suffer temptation and succor the tempted. The account of Tamar acting like a harlot with her father-in-law and her place in Christ's ancestry shows that the Bible records the troubling histories of His ancestors and presents hope to fallen people, even those with inherited sinful tendencies.