921. More about the Night of Yom Kippur

132:4 Some people stand for all of maariv and all day; if they become tired, they lean on something. The reason they stand is to be like the angels. Women do not have the practice to stand. If one stood previously with the intention to do so every Yom Kippur for the rest of his life and he later changed his mind, he must have this commitment annulled.

132:5 Some have the practice to remain in shul and to recite songs of praise all night long. When one needs to sleep, he must distance himself from the ark. (One is only permitted to sleep in shul if he is there to recite the songs of praise – Mishnah Brurah 619:16.) Those who will be leading the services should not stay up because they might lose their voices. Before lying down, they would say the first four Psalms as a prayer against nocturnal emission (“keri”). These Psalms contain 310 words, which is the numerical value of the word “keri.” It is preferable for them not to cover themselves with layers of warm blankets, or at least not to cover their feet.