25:5כ״ה:ה׳
1 א

ויתן אברהם וגו'. אָמַר רַ' נְחֶמְיָה בְּרָכָה דִּיאַתִּיקֵי, שֶׁאָמַר לוֹ הַקָּבָּ"ה לְאַבְרָהָם וֶהְיֵה בְּרָכָה, הַבְּרָכוֹת מְסוּרוֹת בְּיָדְךָ לְבָרֵךְ אֶת מִי שֶׁתִּרְצֶה, וְאַבְרָהָם מְסָרָן לְיִצְחָק (בראשית רבה):

AND ויתן אברהם וגו AND ABRAHAM GAVE etc. — R. Nehemiah said, he gave him the blessing as a legacy (literally, will, testament). The Holy One, blessed be He, had said to Abraham (12:2) “Be thou a blessing” which means “the blessing are entrusted to you that you may bless whomsoever you please”, and Abraham transferred them to Isaac (cf. Genesis Rabbah 61:6).