Genesis 38 is a “parenthetical” chapter inserted by the Holy Spirit to tell you about Judah’s sons. In other words, this chapter falls right in the middle of the history of Joseph, but does not fit chronologically with his history. Judah took his Canaanite bride from Adullam, a place between Bethlehem and Gath, where David hid from Saul in 1 Sam. 22.
Judah’s First Three Sons, v. 3-11
Judah’s wife bare him three sons: Er, Onan, and Shelah. Er, Judah’s wicked firstborn son, married a woman named Tamar, but God killed him before they could have children (1 Chr. 2:3).
So, Judah instructed Onan to marry Tamar and to rear up a son for his dead brother, Er. This wasn’t the law at that time, but this practice eventually became law (Deut. 25:5-10; Matt. 22:24). Onan decided against this because he didn’t want to rear up a child for his brother who would inherit some of Judah’s wealth. He wanted the seed to be his so that he and his own children would receive Judah’s inheritance in the place of his firstborn brother. So, God killed him.
After Onan’s death, Judah promised Tamar to Shelah, the third son, as soon as he was grown. Of course, Judah had no intentions of losing his third child to this woman. Thus, Tamar remained a widow beyond the time that she should have been given to Shelah.
Shelah eventually married, though, and his children are mentioned in 1 Chr. 4:21-23
Judah’s Adultery with Tamar, v. 12-23
Judah went up to his sheepshearers in Timnath and Tamar followed him up there. She pretended to be a harlot and Judah slept with her. He did not realize, at the time, that she was his daughter-in-law. A man could not come in unto his daughter-in-law according to Lev. 18:15, recorded by Moses well after this happened.
Since Judah could not give Tamar a kid for coming in unto her, he gave her his signet, bracelets and staff as a pledge. But when Judah’s friend went to pay her, she was gone with the pledge. The signet that she took would have been engraved (Ex. 28:11; 28:36; Dan. 6:17). Hence, it was easy to identify as Judah’s signet.
Tamar’s Conception, v. 24-26
Within three months, it was obvious that Tamar was pregnant. When news came to Judah, he ordered her to be burnt. This punishment became law for the daughters of the priests (Lev. 21:9).
When Tamar was brought before Judah, she presented the pledge that he had given her. Judah, in humility, acknowledged that he owned the pledge and professed that Tamar was more righteous than he because he had withheld Shelah from her. So, she was not burnt and Judah did not “know” her again.
Judah’s Twins, v. 27-30
The first child to come out was Zarah. The midwife tied a scarlet thread on his wrist to identify him. But before he could be delivered, his brother, Pharez, came out. The name Pharez means “a breach.” See 2 Sam. 6:6-8 for a similar use of the word “breach” transliterated, “Perez.”
As is the case with many other brothers in the Bible, Zarah, the first one doesn’t turn out as good as Pharez, the second one. Consider Cain and Abel, Ishmael and Isaac, Esau and Jacob, and Ephraim and Manasseh.
In Zarah’s genealogy (1 Chr. 2:6-7) we find Achar. He is called Achan in Joshua 7 and he is responsible for the death of 36 men in the battle against Ai.
In Pharez’s genealogy (1 Chr. 2:9-12) we find the line of Christ. His descendants from generation to generation are:
This peculiarity in the Bible (the second child preferred over the first) points to a prophetic warning. The first “Christ” who shows up in the tribulation will be the wrong one. He’ll be the antichrist. The second one to show up will be the right one. He’ll be Jesus Christ!!