When Rabbi Yaakov Mordechai Poltova was on his deathbed, he remarked: "I would give up 40 years of iskafya [spiritual self-refinement] just for the chance to do one more mitzvah." When word of this reached his close friend the Rebbe Rashab, he said: "Indeed he's right. But it takes 40 years of refinement to come to such a clear realization."