Tosefta sobre Shabat 1:13

[With respect to] an am ha'aretz that said to a chaver, "Give me this loaf of bread, and we'll eat it [together]," or "[Give me this] wine and we'll drink it [together]," we do not give it to him, because there is no feeding Tahorot to an am ha'aretz. [With respect to someone who] made a vow on a loaf of bread, and said to him, "Give it to me, and we'll eat it [together]," or a melon that had been pecked [=bitten into by a forbidden animal, see Y. Shab. I.4.9], and he said to him, "Give it to me, and we'll eat it [together]," or an uncovered [jug of] wine, and he said to him, "Give it to me, and we'll drink it [together]," we do not give it to him, because we may not feed a man something that is forbidden to him [as such items are forbidden to all Jews]. Similarly, a Jew may not extend to the sons of Noah the limb [ripped from] a live animal (one of the prohibitions of the seven Noahide laws), and not a cup of wine to a Nazirite, because we do not feed a man something that is forbidden to him. And as to all of these, we do not bless [before eating] over them, and we do not say grace [after meals] over them, and we do not answer "amen" after them (i.e., after their prayers).