וְאַֽחֲרֵי־כֵ֞ן יָצָ֣א אָחִ֗יו וְיָד֤וֹ אֹחֶ֙זֶת֙ בַּעֲקֵ֣ב עֵשָׂ֔ו וַיִּקְרָ֥א שְׁמ֖וֹ יַעֲקֹ֑ב וְיִצְחָ֛ק בֶּן־שִׁשִּׁ֥ים שָׁנָ֖ה בְּלֶ֥דֶת אֹתָֽם׃
And after that came forth his brother, and his hand had hold on Esau’s heel; and his name was called Jacob. And Isaac was threescore years old when she bore them.
Read halakhic rulings (Jewish law) on Genesis 25:26: and classical halakhic sources.