Midrash sa Genesis 31:53: Midrash Tanchuma, Midrash Tehillim & Bereshit Rabbah

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).

Another interpretation: Who will ascend? This refers to our father Jacob, as it is said (Genesis 35:1), "Arise, go up to Bethel and dwell there." Who will stand? This refers to Jacob, as it is said (Genesis 28:11), "And he encountered the place." Clean of hands. This refers to Jacob, as it is said (Genesis 31:38), "I worked for you for fourteen years." And with a pure heart. This refers to Jacob, as it is said (Genesis 37:3), "For he was the son of his old age." "Who did not lift up my soul in vain." This refers to Laban. And he did not swear to deceive, as it is said (Genesis 31:53), "And Jacob swore by the fear of his father Isaac." He will receive a blessing from the Lord, as it is said (Genesis 35:9-10), "And God appeared to Jacob and blessed him."

“The God of Abraham, and the god of Naḥor, the god of their father, will judge between us. Jacob took an oath by the Fear of his father Isaac” (Genesis 31:53).
“The God of Abraham” – sacred, “and the god of Naḥor” – profane, “the god of their father” – its connotation is both sacred and profane.
“Jacob slaughtered for a feast on the mountain, and summoned his brethren to eat bread. They ate bread and stayed the night on the mountain” (Genesis 31:54).
“Laban awoke early in the morning, kissed his sons and his daughters, and blessed them. Laban went and returned to his place” (Genesis 32:1).
“Jacob slaughtered for a feast on the mountain…Laban awoke early in the morning…and blessed them…” – Rabbi Aivu said: They were miserable and deprived against their will, and they gave gifts only with their words. That is what is written: …“Laban awoke early in the morning.”⁴⁵He was unsentimental regarding his daughters and grandchildren, and could not wait to leave.
“Laban went and returned to his place” – to his evil ways. It teaches that robbers entered his house and were vandalizingin it all night.⁴⁶This is expounded from the fact that the verse said that he went to his place and not to his house.