מדרש אויף בראשית 31:48

This heap is witness between me and thee (Gen. 31:48). Scripture states elsewhere in reference to this verse: And crushed Balaam’s foot against the wall (Num. 22:25). The heap alluded to in our text was the very wall at which Balaam violated the promise he had made to Jacob, as it is said: I will not pass over this heap to harm you (Gen. 31:52). Balaam and Laban were one and the same,¹³Sanhedrin 105a. See Ginzberg, Legends of the Jews 6:123. for it is said of him: An Aramean was destroying my father (Deut. 26:5). Balaam was called an Aramean, because he desired to annihilate Israel, as is said: Come, execrate Israel (Num. 23:7). Hence, it was the very wall that had borne witness to the oath that he had made that called him to account, as is written: The hand of the witness shall be first upon him (Deut. 17:7). And Jacob swore by the Fear of his father, Isaac (Gen. 31:53). This righteous man did not swear by the name of the king, but rather on the life of his father. He did it just as a man who desires to prove the truth of this remarks says: “I swear by the life of my father.” He swore this oath only out of respect, as is written: A son shall honor his father (Mal. 1:6).

“Laban called it Yegar Sahaduta and Jacob called it Galed” (Genesis 31:47).
“Laban called it Yegar Sahaduta” – Rabbi Shmuel bar Naḥman said: Let this Persian language³³This is a reference to Aramaic. not be insignificant in your eyes, as in the Torah, in the Prophets, and in the Writings, we find that the Holy One blessed be He pays tribute to it. In the Torah: “Laban called it Yegar Sahaduta”; in the Prophets: “So you shall say to them…” (Jeremiah 10:11);³⁴The entire verse is written in Aramaic. in the Writings: “The Chaldeans spoke Aramaic to the king” (Daniel 2:4).
“And Laban said: This pile is a witness between me and you today, therefore he called it Galed” (Genesis 31:48).
“And the Mitzpa, as he said: The Lord will observe between me and you, because we will be concealed one from the other” (Genesis 31:49).
“And the Mitzpa, as he said: The Lord will observe [between me and you, because we will be concealed [ki nisater]]” – Rabbi Abbahu said: “Ki yisater” is not written here, but rather, “ki nisater.”³⁵The singular – yisater – can mean that one hides from the other. The plural – nisater – infers that both of them maintain their distance from each other. Until now we have been seeing one another, from now on we will not be seeing one another.
“If you afflict my daughters, or if you take wives in addition to my daughters, though no one else be about; see, God is witness between me and you” (Genesis 31:50).
“If you afflict my daughters” – Rabbi Reuven said: They were all his daughters – “the girls are my daughters” (Genesis 31:43).³⁶See subsection 13.
“If you afflict my daughters” – you will not take [other] wives during their lifetime; “if you take wives in addition to my daughters” – after their deaths;³⁷Even after their deaths you should not take another wife. “see, God is witness between me and you.”