וַיֹּ֣אמֶר אֵלַ֗י הִנְנִ֤י מַפְרְךָ֙ וְהִרְבִּיתִ֔ךָ וּנְתַתִּ֖יךָ לִקְהַ֣ל עַמִּ֑ים וְנָ֨תַתִּ֜י אֶת־הָאָ֧רֶץ הַזֹּ֛את לְזַרְעֲךָ֥ אַחֲרֶ֖יךָ אֲחֻזַּ֥ת עוֹלָֽם׃
and said unto me: Behold, I will make thee fruitful, and multiply thee, and I will make of thee a company of peoples; and will give this land to thy seed after thee for an everlasting possession.
Read kabbalistic (mystical) interpretation of Genesis 48:4: and classical mystical sources.