וַיֹּ֣אמֶר לָבָ֔ן לֹא־יֵעָשֶׂ֥ה כֵ֖ן בִּמְקוֹמֵ֑נוּ לָתֵ֥ת הַצְּעִירָ֖ה לִפְנֵ֥י הַבְּכִירָֽה׃
And Laban said: ‘It is not so done in our place, to give the younger before the first-born.
Read halakhic rulings (Jewish law) on Genesis 29:26: and classical halakhic sources.