1. Requirements of נטילת ידים (כח גברא, כלי of a רביעית)

Rav Pappa discussed אריתא דדלאי – a water canal from which water is drawnby pail and poured into a ditch. Dipping one’s hands into the ditch does not qualify for נטילת ידים, דלא אתו מכח גברא – because [the waters] do not come onto his hands through human force, but flow by themselves. It also does not qualify for טבילת ידים – immersing the hands, since it lacks forty סאה. However, he may dip his hands near where the water is poured from the pail. Also, if water streams through a sizeable hole in the pail back into the canal while he pours into the ditch, he may immerse his hands in the ditch, because it is connected to forty סאה. Rava teaches that a כלי with a hole בכונס משקה – which takes in liquid, or with less than a רביעית of water, is invalid for נטילת ידים. Although Rava taught that a כלי which cannot contain a רביעית is invalid for נטילת ידים, implying that one which can contain a רביעית is valid even with less than a רביעית inside, that refers to washing a second person’s hands, which do not require a רביעית, דקאתו משירי טהרה – because [these waters] come from remnants of [water used for] purification.

1. נטילת ידים when eating without touching food (מפה, one person feeding another)

The Gemara asks: מהו לאכול במפה – what is the halachah regarding eating bread with a cloth; is נטילת ידים required? מי חיישינן דלמא נגע – Are we concerned that perhaps he may still touch the bread, or not? Shmuel is quoted: התירו מפה לאוכלי תרומה – they permitted eating with a cloth for those who eat terumah (i.e., Kohanim, who are especially conscientious and will not touch the terumah), ולא התירו מפה לאוכלי טהרות – but they did not permit eating with a cloth for those who eat [tahor foods], i.e., those who are careful to eat chullin which is tahor. The Gemara asks if someone who is being fed by another person needs to wash his hands, and later asks if the person feeding him must wash his hands. It relates that Shmuel was once crying as a child because his teacher hit him for feeding his son without washing his own hands. Shmuel explained to his father: הוא אכיל ואנא משינא – “He is eating, and I should wash my hands?!” Shmuel’s father declared, “Is it not enough that the teacher did not learn the halachos of נטילת ידים, but he hits as well?!” The halachah is that אוכל מחמת מאכיל – one who is eating via someone feeding him requires נטילת ידים, but מאכיל – the feeder does not.

1. Two people eating at the same table, one meat and one dairy

The next Mishnah permits wrapping meat and cheese into a single cloth, ובלבד שלא יהו נוגעין זה בזה – provided they do not touch each other. Abaye explains that if they would touch each other, although they are צונן בצונן – cold with cold and do not transfer flavor, הדחה – rinsing would be required to remove residue from the other food. Rabban Shimon ben Gamliel says: שני אכסנאין אוכלין על שלחן אחד – two guests at an inn may eat on one table, this one meat and this one cheese, and we are not concerned that one will eat from the other’s food. However, Shmuel says that מכירין זה את זה – if they know each other, they may not eat at one table, one meat and one dairy, because one might eat the other’s food. In a Baraisa, Rabban Shimon ben Gamliel forbids two people who know each other to eat meat and dairy כעין תפיסה אחת – when it is similar to food together in a bundle, i.e., without a distinct object between them. Two brothers who are particular not to eat from each other are still forbidden to share a table of meat and dairy, because observers may conclude that people may always eat together this way.