Genesis 38:29
And it came to pass, as he drew back his hand, that, behold, his brother came out: and she said, How hast thou broken forth? this breach be upon thee: therefore his name was called Pharez. And it came to pass, as he drew back his hand, that, behold, his brother came out: and she said, How hast thou broken forth? this breach be upon thee: therefore his name was called Pharez.
The verse recounts the birth of Perez, when after his twin brother Zerah drew back his hand Perez himself came out first, and the name Perez marks this unexpected breach by which the second came ahead of the first.
It belongs to the Genesis 37-41 account of Joseph's early life, including the envy of his brothers, his sale as a slave to the Ishmaelites, his sojourn in Egypt, and God's wondrously good dealings with him through it all.
It is part of the record of Judah's sin, given to expose sin so that it may be shunned and to point to God's love, mercy, and power as its remedy.
It belongs to the account of Tamar, who acted as a harlot with her father-in-law and stands as an ancestor of Jesus, showing that God's record of His human ancestors includes people with shameful histories and giving hope to the fallen.
It identifies Pharez, born to Tamar out of harlotry in an unlawful union, as an ancestor of Christ according to the flesh, placing him in a human lineage marked by sin, degradation, and weakness.
Christ came through that ancestry and shared the infirmities of fallen human nature as part of the plan of redemption.
The fallen, deteriorated flesh Christ assumed concentrated the weaknesses and sinful tendencies of humanity and was more subject to infirmity than unfallen humanity, so that death could have power over Him and He could suffer temptation and sympathize with man in order to redeem him.