Yadayim 1:1-2

Yadayim 1:1

For ritual washing, a revi’is of water (around 3 oz.) must be poured over the hands for one person, or even two. Half a log (around 6.5 oz.) must be poured over the hands for three or four people. A full log (around 13 oz.) is sufficient for five, ten or 100 people. Rabbi Yosi says that this is as long as there’s not less than a revi'is left for the last person among them. More water may be added to the second pouring but not to the first.

Yadayim 1:2

Water may be poured over the hands from any kind of vessel, including those made of dung, stone and clay. One may not pour water from the sides of (broken) vessels, nor from the bottom of a ladle or the stopper of a barrel, nor may one pour water over his friend’s hands from his own cupped hands. This is because one may only draw, sanctify and sprinkle the purification waters, and one may only pour water over the hands, by using a vessel. Furthermore, only vessels closed with a tight lid protect their contents from corpse impurity, and only vessels protect their contents from impurity inside earthenware vessels.