Tafsiran Kejadian 31:52: Rashi, Chizkuni, Da'at Zekenim & Radak

אם אני THAT I WILL NOT — Here the word אם is used in the sense of אשר “that”, as (Genesis 24:33) “until that (אם) I have spoken my words”.

אם אני לא אעבור עליך, “I will not cross this stonepile with hostile intent against you. Lavan undertakes not to join anyone bent on attacking Yaakov in return for Yaakov’s promise not to do this in the event that he will be attacked.

עד הגל הזה, “this stone heap (plus the monument mentioned in the same verse) is to serve as two witnesses;” they fastened a sword to this monument as a symbol; this is why Bileam was struck both by a sword as well as by becoming lame, when his leg was squeezed against a stonewall by his she-ass, Numbers 22,25. Bileam is identified as Lavan, same as kushan rishatayim (according to the Zohar on Chayey Sarah page 126.) We find something similar in the case of a young man who became betrothed to a young lady and swore an oath to her not to marry another woman in addition to her. As proof of his sincerity he gave her a polecat and a cistern After a year, he married another woman who bore him two children. One of his children was fatally injured by a polecat, the other drowned in a cistern. In other words, each one of his children was killed by one of his witnesses to the oath he had broken. (Compare Talmud, tractate Taanit, folio 8, and Rashi’s commentary on that paragraph.) We can also find an allusion to this in the wording of Deuteronomy 17,7: יד העדים תהיה בו בראשונה, “the hand of the witnesses shall be the first upon him, etc.”

לרעה FOR EVIL — For evil you may not pass, but for trading purposes (as e. g., with a caravan) you may pass (Genesis Rabbah 74:16).