(8) Go in unto thy brother's wife.--We learn from this that the law of the Levirate, by which the brother of the dead husband was required to marry the widow, was of far more ancient date than the law of Moses. Its object, first of all, was to prevent the extinction of any line of descent, a matter of great importance in those genealogical days; and, secondly, it was an obstacle to the accumulation of landed property in few hands, as the son first born after the Levirate marriage inherited the property of his deceased uncle, while the second son was the representative of the real father. A similar custom existed in parts of India, Persia, &c, and prevails now among the Mongols. The Mosaic Law did not institute, but regulated the custom, confining such marriages to cases where the deceased brother had died without children, and permitting the brother to refuse to marry the widow, under a penalty, nevertheless, of disgrace. Onan, by refusing to take Tamar, may have been actuated by the selfish motive of obtaining for himself the rights of primogeniture, which would otherwise have gone to his eldest son, as the heir of his uncle 'Er.

Verse 8. - And Judah said unto Onan (obviously after a sufficient interval), Go in unto thy brother's wife, and marry her, - literally, and perform the part of levir, or husband's brother, to her. The language seems to imply that what was afterwards in the code Mosaic known as the Lex Leviratus (Deuteronomy 25:5, 6) was at this time a recognized custom. The existence of the practice has been traced in different frames among Indians, Persians, and other nations of Asia and Africa - and raise up seed to thy brother. As afterwards explained in the Hebrew legislation, the first. born son of such a Levirate marriage became in the eye of the law the child of the deceased husband, and was regarded as his heir.

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.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.