Question: [Tuesday, 13th Tamuz 5782]
My toddler walked into the room in the morning, and I caught her taking a sip from the water in my Neigal Vaaser cup that I had set up the night before to use for washing when I wake up. My question is regarding if I may still use this water for the morning washing or if it has become invalid.
The water remains valid and may still be used for washing hands in the morning, or for bread.
Explanation: The rule regarding washing hands for bread is that any water which had work done with it is invalid for the washing. Thus, for example, if one washed dirty vegetables in water then that water is invalid. Likewise, if one washed his hands that were dirty in the water, the entire water that is in the vessel is invalid, even if he only entered his hand into the top part of the water, and even if one only entered one pinky into it to wash dirt from it. Now, the question is raised as to whether drinking from the cup of water is defined as doing work to the water. So, we find an explicit ruling regarding an animal [except dog and pig] who drinks from a cup of water, that the remaining water in the cup still remains valid for washing hands for bread, as the Melacha was only done to the water that entered the mouth, and even if some water was spat back into the vessel from the mouth, it is nullified in majority. Now, we can apply the same law regarding a vessel of water which a person drank from, that he has the same status as any other animal [and not a dog or pig] and that the remaining water is valid. This would certainly apply towards using the water for washing after awakening, which itself is under debate if Melacha invalidates it.
Sources: See regarding Melacha done to water to be used for washing hands for bread: Admur 160:2-7; Seder Netilas Yadayim 10; See regarding if the drinking of an animal invalidates the water: Admur 160:8; Seder Netilas Yadayim 11; M”A 160:7; Rambam Mikvaos 11:9; Ketzos Hashulchan 160:5; See regarding if Matlacha invalidates water for washing hands in the morning: Invalidates: Siddur Seder Netilah; Peri Tzaddik 74; Mamar Mordechai 4:3; Nivei Shalom 4:2; Kaf Hachaim 4:11; Mor Uketzia brought in Kaf Hachaim 4:27; Does not invalidate: Kama 4:3; Michaber 4:1; M”A 4:5; Derisha; Levush