Midrash su Ecclesiaste 5:4

Better is it that thou shouldst not vow, than that thou shouldst vow and not pay (Eccles. 5:4). R. Meir maintained: Better than either of these is that one should not vow at all. A man should bring his lamb to the Temple court and sacrifice it instead. R. Judah was of the opinion that to make a vow and fulfill it was preferable to the other two, since it is said: Vow, and pay unto the Lord your God (Ps. 76:12). He who makes a vow and performs it is rewarded both for the vow and its fulfillment.

It is written (in Ps. 50:14): SACRIFICE A THANK OFFERING TO GOD. When Jacob left his father's house, he left with nothing but his staff, as stated (in Gen. 32:11 [10]): WITH ONLY MY STAFF I CROSSED THIS JORDAN. Immediately Jacob had made a vow before the Holy One, as stated (in Gen. 28:20): THEN JACOB VOWED A VOW. What is written at the end of the passage (in vs. 22)? AND OF ALL THAT YOU GIVE ME. But, when he enriched him, as stated (in Gen. 30:43): SO THE MAN (Jacob) BECAME VERY VERY PROSPEROUS, he forgot his vow. Immediately he provoked Laban against him, as stated (in Gen. 31:23): SO HE (Laban) TOOK HIS RELATIVES WITH HIM < AND PURSUED HIM (Jacob) SEVEN DAYS' JOURNEY >. When he had escaped from Laban, Esau was incited against him. Immediately the angel appeared to him. He said to him: Are you not aware of all this trouble? Why has all the trouble come over you? Because you have been late with your vow. Jacob said to him (in Gen. 32:30 [29]) {WHAT IS} [PLEASE TELL] YOUR NAME. He said to him (ibid.): WHY IS IT THAT YOU ARE ASKING FOR MY NAME? Sometimes the angel is made into a spirit, as stated (in Ps. 104:4): HE HAS MADE HIS ANGELS SPIRITS. Sometimes he is made a into lightning bolt, as stated (in Job 38:35): CAN YOU SEND FORTH LIGHTNINGS SO THAT THEY GO? But as for the miracles (of transformation), he (God) acts himself. And so the angel said to Manoah (in Jud. 13:18): YOU ARE NOT TO ASK MY NAME. (Gen. 32:30 [29]:) WHY IS IT THAT YOU ARE ASKING FOR MY NAME?⁷⁴Yalqut Shim‘oni, Jud., 69, explains that names are useless because the angel would not know into what form God might change him. Immediately the angel blessed him, as stated (in Gen. 32:30 [29]): AND HE BLESSED HIM THERE. (Hos. 12:5 [4]:) SO HE STROVE WITH AN ANGEL AND PREVAILED. What did he say to him? Go, fulfill your vow. (Eccl. 5:4 [5]:) IT IS BETTER NOT TO VOW < THAN TO VOW AND NOT FULFILL >. What did Simeon and Levi do immediately? TWO OF JACOB'S SONS, [SIMEON AND LEVI, BROTHERS OF DINAH, EACH TOOK HIS SWORD] … < AND KILLED EVERY MALE >. < Jacob > immediately fell on his face and did not get up until < the Holy One > gave him permission (in Gen. 35:1): ARISE, GO UP TO BETHEL. So also with Joshua (according to Josh. 7:6 & 10): [AND HE FELL ON HIS FACE] < .. . > THEN THE LORD SAID UNTO JOSHUA: ARISE, GO. WHY IS IT THAT YOU FALL UPON YOUR FACE? So also with David (according to I Chron. 21:16): SO DAVID AND THE ELDERS, COVERED IN SACKCLOTH, FELL UPON THEIR FACES. Then what was said to him (in II Sam. 24:18)? GO UP, ERECT AN ALTAR TO THE LORD ON THE THRESHING FLOOR OF ARAUNAH. It is therefore stated (in Gen. 35:1): ARISE, GO UP TO BETHEL. He immediately journeyed with his whole house; and the Holy One put his fear upon all about him, as stated (in Gen. 35:5): AND, AS THEY JOURNEYED, A TERROR FROM GOD CAME < UPON THE CITIES THAT WERE ROUND ABOUT THEM >. It is also stated (in Deut. 28:10): AND ALL THE PEOPLES OF THE EARTH SHALL SEE THAT THE NAME OF THE LORD IS PROCLAIMED OVER YOU, AND THEY SHALL BE AFRAID OF YOU.