This is a Rabbinic Mitzvah: Eruvin 21b
When King Solomon created this decree, a Divine Voice announced, "My son, if your heart is wise, My Heart is glad!": Eruvin 21b
Amount of food which requires hand-washing: Succah 26b, 27a
Washing before Touching bread, because of Shaidim-Spirits: Yoma 77b
Washing before touching vegetables dipped in one of the 7 Liquids which Enable Communication of Impurity: Pesachim 115a-b
Requiring a new Hand-Washing if one's attention was drawn away after the first one: Pesachim 115b
Hand-washing in a military camp:Eruvin 17a, 17b
Procedure
Requiring a Reviit of water: Gittin 15b
Two people washing from the same pouring of a Reviit of water: Gittin 15b
One must travel 1 or 4 Mil to find water: Pesachim 46a
Washing one hand, and immersing the other in a Ritual Bath [Mikvah]: Gittin 15b
Washing hands in segments; depends on the wetness of the part which was washed first: Gittin 15b-16a
Raising one's hands, to keep the water at the wrist end from coming back on to one's hands: Sotah 4b
The importance of drying one's hands, to prevent the bread from becoming wet: Sotah 4b
Interruptions between Hand-Washing and Eating Bread
When R' Akiva was in jail, R' Yehoshua haGarsi would bring him water. Once the jailor poured out half the water, and R' Akiva insisted on using what remained to wash his hands for his meal rather than to drink, saying, "What can I do? The punishment for violating the words of the rabbis is Death!": Eruvin 21b
Comparison between disdaining this Mitzvah and being involved in adultery: Sotah 4b
The punishment for disdaining this Mitzvah is poverty, or is being "uprooted" from the world: Sotah 4b Ex-communication for disdaining this mitzvah: Berachot 19a
