Question (Mishnah further on): 'A Chaver laborer who does not trust (that) his employer (tithed) should...'. This shows that usually an employer should tithe before he gives the produce to his poor laborers as payment (because one may not use Demai as payment). But here, Rabban Gamliel said that one may pay his laborers with Demai...?

Answer (R. Yona): There, it looks like he is paying him as a poor laborer; but here, it looks like he is eating from the central bowl (as a household member).

(R. Zerikan/Shimon bar Vava citing R. Yochanan): If a Chaver doctor was feeding a sick Am HaAretz, he should put the food into the patient's hand rather than directly into his mouth.

This applies to Demai, but if it was definite Tevel, he may not even put it into his hand. The permission to give him Demai only applies if it is the patient's Demai, but if it belongs to the doctor, it is prohibited.

The prohibition to put Tevel into the patient's hand applies to a sick Jew, but if he is a gentile, even if it is definite Tevel, it is permitted. However, even if the patient is a gentile, if it belongs to the doctor, it is prohibited.

And if it was a limb severed from a live animal, even if it belonged to the gentile patient, it is prohibited, so that the gentile shouldn't come to transgress.