וַתֵּ֤לֶד הַבְּכִירָה֙ בֵּ֔ן וַתִּקְרָ֥א שְׁמ֖וֹ מוֹאָ֑ב ה֥וּא אֲבִֽי־מוֹאָ֖ב עַד־הַיּֽוֹם׃
And the first-born bore a son, and called his name Moab—the same is the father of the Moabites unto this day.
Targum Jonathan on Genesis
And the elder brought forth a son, and she called his name Moab, because from her father she had conceived. He is the father of the Moabaee unto this day.