(3) If a person makes a vow to ה' or takes an oath imposing an obligation*an obligation Or “a prohibition.” on himself, he shall not break his pledge; he must carry out all that has crossed his lips.*crossed his lips Lit. “come out of his mouth.”
Dean: Do not make such broad vows because Jephthah made his vow too broad and he ended up having to sacrifice his daughter because he did not consider what might happen.
Ben: If you make a vow its like gambling. You can lose or gain somebody's trust by completing or not completing a vow you make. You are not sure when you make the vow if you can fulfill it or not when you make it.
Sam: We are supposed to think of G-d like our parent. But, I would never have spoken like to G-d like Moses did to my mother. She would punish me for mouthing off! Moses was sort of mouthing off to G-d.