Tosefta su Deuteronomio 7:2

Always they circumcise idolators in the name of [becoming] a ger, but idolators do not circumcise Jews because they are suspected of taking lives, according to Rabbi Meir. But the Sages say, an idolator may circumcise a Jew in a time when others are standing over him, but if they are alone, it is forbidden because they are suspected of taking lives. A Jew may circumcise a Samaritan, but a Samaritan may not circumcise a Jew because they circumcise in the name of Mt. Gerizim, according to Rabbi Yehuda. Rabbi Yosei said to him, Where do we find circumcision in the Torah that it is not in the name of the covenant? Rather, let him circumcise in the name of Mt. Gerizim until he dies! One may buy from them and give them an undeserved gift. Of what does this speak? In a time when he is not selling it to him or if he was going from place to place. But if he was his neighbor or his field, this is permitted, because it is like selling to him. The scripture says, “grant them no terms (brit) and give them no quarter (t’chaneim)” (Deut 7:2). If to teach about the covenant, look it speaks of the brit, but why is it said, “give them no quarter (lo t’chaneim)”? To teach that you do not give them unearned gifts.