Why Jacob's Forgotten Vow Brought Esau and the Angel Upon Him

It is written (Psalms 50:14): "Offer to God a thank-offering." When Jacob went out from his father's house, he went out with nothing but his staff, as it is said (Genesis 32:11): "For with my staff I crossed this Jordan." At once Jacob vowed a vow before the Holy One, blessed be He, as it is said (Genesis 28:20): "And Jacob vowed a vow." What is written at the end of the matter? (Genesis 28:22): "And of all that You give me." And once he had grown rich, as it is said (Genesis 30:43): "And the man increased exceedingly," he forgot his vow. At once He incited Laban against him, as it is said (Genesis 31:23): "And he took his brethren with him." And he was delivered from Laban, and Esau was incited against him. At once the angel was revealed to him. He said to him: Do you not know all this trouble? Why has all this trouble come upon you? Because you delayed your vow. Jacob said to him (Genesis 32:30): "Tell me, I pray, Your name." He said to him (ibid.): "Why is it that you ask after My name?" At times the angel becomes wind, as it is said (Psalms 104:4): "He makes His angels winds." At times he becomes lightning, as it is said (Job 38:35): "Can you send forth lightnings, that they may go?" And according to the miracles, he makes himself accordingly. And likewise the angel said to Manoah (Judges 13:18): "Why is it that you ask after my name?" At once the angel blessed him, as it is said (Genesis 32:30): "And he blessed him there." (Hosea 12:5): "And he strove with an angel and prevailed." What did he speak with him? He said to him: Go, fulfill your vow. (Ecclesiastes 5:4): "It is good that you should not vow." At once, what did Simeon and Levi do? (Genesis 34:25): "And they took, the two sons of Jacob, Simeon and Levi, Dinah's brothers, each man his sword." At once he fell upon his face, and he did not rise until He gave him permission (Genesis 35:1): "Arise, go up to Bethel." And likewise with Joshua (Joshua 7:6, 10): "And he fell upon his face," "And the Lord said to Joshua: Arise, get you up; why is it that you have fallen upon your face?" And likewise with David (1 Chronicles 21:16): "And David and the elders, clothed in sackcloth, fell upon their faces." And what was said to him? (2 Samuel 24:18): "Go up, raise up to the Lord an altar in the threshing-floor of Araunah." Therefore it is said: "Arise, go up to Bethel." At once he journeyed, he and all his house, and the Holy One, blessed be He, set the dread of him upon all those around him, as it is said (Genesis 35:5): "And they journeyed, and the terror of God was upon the cities." And it is said (Deuteronomy 28:10): "And all the peoples of the earth shall see that the name of the Lord is called upon you, and they shall fear you."