15:18ט״ו:י״ח
1 א

לזרעך נתתי. אֲמִירָתוֹ שֶׁל הַקָּבָּ"ה כְּאִלוּ הִיא עֲשׂוּיָה:

לזרעך נתתי UNTO THY SEED HAVE I GIVEN — The promise of the Holy One, blessed be He, is as an accomplished fact. (Consequently the perfect tense is here used) (Genesis Rabbah 44:22).

2 ב

הנהר הגדול. לְפִי שֶׁהוּא דָבוּק לְאֶרֶץ יִשְׂרָאֵל קוֹרְאֵהוּ גָּדוֹל, אַעַ"פִּ שֶׁהוּא מְאֻחָר בְּאַרְבָּעָה נְהָרוֹת הַיּוֹצְאִים מֵעֵדֶן, שֶׁנֶּאֱמַר וְהַנָּהָר הָרְבִיעִי הוּא פְרָת. מָשָׁל הֶדְיוֹט: עֶבֶד מֶלֶךְ מֶלֶךְ, הִדָּבֵק לַשַּׁחֲוָר וְיִשְׁתַּחֲווּ לְךָ (בראשית רבה):

הנהר הגדול THE GREAT RIVER—Because it is associated with (mentioned in connection with; see Rashi on Deuteronomy 1:7) the land of Israel, Scripture calls it “great” although it is the last mentioned of the four rivers that went out of Eden — as it is said (Genesis 2:14). And the fourth river is the Euphrates”. There is a popular proverb: “A king’s servant is a king; attach yourself to a captain and people will bow down to you” (Genesis Rabbah 16:3).