I heard a class about the rabbinic prohibition against separating Maaser at a significant distance from the Tevel (שלא מן המוקף). The Rabbi mentioned that one is allowed to violate this prohibition* and separate Maaser at a distance only in order to save someone who is about to eat Tevel, which is a more stringent Torah-prohibition. What is the source for allowing one to violate this rabbinic prohibition in order to save another from the Torah prohibition of eating Tevel?
- The obligation to take Maaser Min Hamukaf is Deorayita for Tevel Deorayita. Learned from a Drasha on the verse Bamidbar 18.26. See Tosfot Yevamot 93b and Rishonim there. But if someone makes it at distance, the Teruma is valid, as we see for more examples of incorrect procedures in Temura 5a.