Vows, Oaths and Pledges in Noahide Law
Rabbi Yoel Schwartz (Jerusalem Court for Bnei Noah)
A pledge is a positive mild commitment, “If I can, I will.” It is a matter of conscience and ability to fulfill. It is probably appropriate that it should be fulfilled.
A vow is a commitment made to someone else. It should be fulfilled because of the obligation to abide by the laws of interpersonal relationships. An oath is an unconditional commitment. When undertaken in the name of G-d it must be honored because of one’s duty to respect G-d. Abraham made Eliezer place his hand under his thigh and swear by an oath (Genesis 24:2-3). A person must keep all vows, and oaths he made, especially if he has promised to give alms to the needy or a sacrifice to G-d.