fellow students recall menachem shmuel dovid's meticulous observance of the mitzvot and his passionate way of prayer. his shabbat morning prayer ritual would last as long as six hours, and included lengthy meditations in the chabad tradition. at night, when reciting the bedtime prayers, raichik would often become engrossed in introspection into the wee hours, when the time came for morning prayers. during the day he employed his sharp mind in deep talmudic study.