And Judah said unto Onan,.... Some time after his brother's death:

go in unto thy brother's wife, and marry her; Moses here uses a word not common for marriage, but which was peculiar to the marrying of a brother's wife according to a law given in his time: it appears to have been a custom before, and which the patriarch might be directed to by the Lord, in such a case when a brother died, and left no issue, for the sake of multiplication of seed, according to the divine promise, and which in the time of Moses passed into a law, see Deuteronomy 25:5,

and raise up seed unto thy brother; that might bear his name, and enjoy his inheritance. For this law or custom was partly political, to continue the paternal inheritance in the family, and partly typical, to direct to Christ the firstborn among many brethren, Romans 8:29, who in all things was to have the preeminence, Colossians 1:18; and this was not taken from the Canaanites, among whom Judah now was, but from the ancient patriarchs, which they had no doubt from divine revelation, and was taught in the school of Shem, and handed down from father to son; for as to this being a law among the Egyptians in later times, and which continued to the days of Zeno Augustus (q), it is most likely they took it from the Jews.

(q) Justinian. Cod l. 5. Titus 6. leg. 8.

And Judah said unto Onan, Go in unto thy brother's wife, and marry her, and raise {c} up seed to thy brother.

(c) This order was for the preservation of the stock, since the child begotten by the second brother would have the name and inheritance of the first: a practice which is abolished in the New Testament.

8. Judah said unto Onan . marry her, and raise up seed to thy brother-The first instance of a custom, which was afterwards incorporated among the laws of Moses, that when a husband died leaving a widow, his brother next of age was to marry her, and the issue, if any, was to be served heir to the deceased (compare De 25:5).

38:1-30 The profligate conduct of Judah and his family. - This chapter gives an account of Judah and his family, and such an account it is, that it seems a wonder that of all Jacob's sons, our Lord should spring out of Judah, Heb 7:14. But God will show that his choice is of grace and not of merit, and that Christ came into the world to save sinners, even the chief. Also, that the worthiness of Christ is of himself, and not from his ancestors. How little reason had the Jews, who were so called from this Judah, to boast as they did, Joh 8:41. What awful examples the Lord proclaims in his punishments, of his utter displeasure at sin! Let us seek grace from God to avoid every appearance of sin. And let that state of humbleness to which Jesus submitted, when he came to put away sin by the sacrifice of himself, in appointing such characters as those here recorded, to be his ancestors, endear the Redeemer to our hearts.