וְהִתְבָּרֲכ֣וּ בְזַרְעֲךָ֔ כֹּ֖ל גּוֹיֵ֣י הָאָ֑רֶץ עֵ֕קֶב אֲשֶׁ֥ר שָׁמַ֖עְתָּ בְּקֹלִֽי׃
and in thy seed shall all the nations of the earth be blessed; because thou hast hearkened to My voice.’
Read midrashic interpretation of Genesis 22:18: and classical rabbinic exegesis.