Deuteronomy 25:6

And it shall be, [that] the firstborn which she beareth shall succeed in the name of his brother [which is] dead, that his name be not put out of Israel.

Ver. 6. The first born.] Provided that he be a son; as appears by the reason here given, that his name be not put out of Israel. It signified the birthright of Christ that should never die. "He shall see his seed, he shall prolong his days." Isa 53:10 Filiabitur nomen eius Psa 72:17 The name of Christ shall endure for ever; it shall be begotten as one generation is begotten of another; there shall be a succession of Christ's name.