創世記 28:15

אנכי עמך I AM WITH THEE — God promised him this because he was in terror of Esau and Laban. עד אשר אם עשיתי UNTIL I HAVE DONE — The word אם is here used in the sense of כי (cf. Gittin 90a). דברתי לך means I have spoken in thy interest and concerning thee: whatever I promised to Abraham regarding his seed it was in reference to you that I promised it and not in reference to Esau, for I did not say to him “Isaac shall be called thy seed” (which would have signified that all Isaac’s descendants would be regarded, also, as Abraham’s) but I said (21:12) ביצחק “In Isaac” and not all the issue of Isaac”. In the same way wherever לי or לך or לו or להם are used after a verbal form of דבר, they are used in the sense of “concerning”. This verse proves that this is so, since it cannot mean “I have spoken to thee” as He had never spoken to Jacob before this occasion.

וְהִנֵּ֨ה אָנֹכִ֜י עִמָּ֗ךְ וּשְׁמַרְתִּ֙יךָ֙ בְּכֹ֣ל אֲשֶׁר־תֵּלֵ֔ךְ וַהֲשִׁ֣בֹתִ֔יךָ אֶל־הָאֲדָמָ֖ה הַזֹּ֑את כִּ֚י לֹ֣א אֶֽעֱזׇבְךָ֔ עַ֚ד אֲשֶׁ֣ר אִם־עָשִׂ֔יתִי אֵ֥ת אֲשֶׁר־דִּבַּ֖רְתִּי לָֽךְ׃

And, behold, I am with thee, and will keep thee in all places to which thou goest, and will bring thee back to this land; for I will not leave thee, until I have done that which I have spoken to thee of.