Let Hashem Owe You Instead of You Owing Hashem
Someone pledged to give money if a certain close relative would be healed from an illness. The Rashab said to him, "give the money before that person is healed, so that Hashem will owe you, instead of waiting until after he is healed, and you owe Hashem."
The Rebbe Rashab P498
Beis Nisan (1920) Yom hillula of the 5th Chabad Rebbe Admor Shalom Dov Ber – Rashab.