283. Feeding the Waiter
42:14 If someone is eating food that was served to him and the aroma is appetizing, he should give a small piece to the one who brought it to him, since seeing food and desiring it but being unable to taste it isn’t good for a person. (This applied in times and places where household servants did not eat the same types of food as they served. Nowadays, if you go to a friend’s house, a wedding or a restaurant, you need not worry about feeding the waiter – Bi’ur Halacha 169:1 s.v. “miyad.”)
42:15 We should only give food to people if we know that they will wash their hands and say the blessing before eating bread. (This applies specifically to the waiter in the previous halacha; since he is occupied with serving, he may forget his religious obligations. In other cases, there is room to be lenient in this matter – Mishnah Brurah 169:9.)