The Messiah would come from the lineage of Isaac.
OT Prophecy NT Fulfillment
Genesis 21:12
"And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called."
Luke 3:23-34
[23] And Jesus himself began to be about thirty years of age, being (as was supposed) the son of Joseph, which was the son of Heli...
...[34] Which was the son of Jacob, which was the son of Isaac, which was the son of Abraham, which was the son of Thara, which was the son of Nachor.
Tanakh - Bereshit - Genesis 21:12
"And G-d said unto Abraham: 'Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah saith unto thee, hearken unto her voice; for in Isaac shall seed be called to thee.'"
Hebrew OT - Genesis 21:12
וַיֹּאמֶר אֱלֹהִים אֶל־אַבְרָהָם אַל־יֵרַע בְּעֵינֶיךָ עַל־הַנַּעַר וְעַל־אֲמָתֶךָ
כֹּל אֲשֶׁר תֹּאמַר אֵלֶיךָ שָׂרָה שְׁמַע בְּקֹלָהּ
כִּי בְיִצְחָק יִקָּרֵא לְךָ זָרַע