The Ruling on Unconditional Vows

Question:
If the vow is not conditional, is it permissible?

Answer:
If it is an act of obedience, it is obligatory. He said, “I pledge to Allah that I will do such and such,” as an act of obedience; it is obligatory . But if he says, “If Allah wills,” or “I will do it if Allah wills,” it does not become a vow. Or if he says, “If I am present, I will do it,” and he has not committed himself to it, it does not become a vow... Or if he says, “If I stay with them, I will give a lesson,” or “If I find so-and-so, I will advise him,” that is a promise.