Ben Waldbaum from Washington University, St. Louis wrote:
I heard someone advise a student at my university that they can say, "I will study five pesukim (Torah verses) this week if You, G-d, give me an "A" on an exam." Is someone allowed to say this? If it is allowed, why is it not considered testing Hashem? Thanks a lot!
Dear Ben Waldbaum,
Did he mean that he will study the Torah verses first, and as a result he expects G-d to reward him with an "A" on the exam? If so, this is considered testing G-d and is forbidden. (One may test G-d only in regard to giving tithes and charity.)
Or did he mean that if he gets an "A" he will then study five Torah verses? If so, this is not testing G-d. Rather, it's like a conditional vow. It's like saying: "If I get an A, then I vow to study five verses. But if not, then not."
In this week's Torah portion, Jacob made a conditional vow: "Jacob took a vow saying: If G-d will be with me...give me bread to eat and clothes to wear, and I return in peace to my father's house... then this stone which I have set up as a pillar shall become a house of G-d...." (Bereishet 28:21-2).
However, a person should not make vows, because the punishment for breaking a vow is very severe. Furthermore, making a vow smacks of arrogance, like saying, "I'm so perfect that, not only do I fulfill 100% of my obligations to G-d, but I'm even taking on extra obligations!"
- Shulchan Aruch Yoreh De'ah 247:4