Q&A: A Torah-level doubt is treated stringently by rabbinic law
A Torah-level doubt is treated stringently by rabbinic law
Question
According to Maimonides' view, many later authorities ask: in a case where one is in doubt whether he recited Grace after Meals (which is a Torah-level doubt), and therefore he must go back and recite it again by rabbinic law, why are we not concerned about "Do not take [God's name in vain]," which is a Torah prohibition? So how can he repeat the blessing? In any case, I didn't understand the question, because here too we are entering a doubt regarding "Do not take [God's name in vain]"—perhaps he already recited it—and that prohibition itself is also only rabbinic in a case of doubt, on the principle of "they said it and they said it."
Answer
There is a lot to analyze here. On the possibility that he already recited it, then he is under no obligation to recite it, and therefore the prohibition of "Do not take [God's name in vain]" is not overridden. This is like the dispute whether a doubtful positive commandment overrides a doubtful prohibition (the Sdei Chemed discusses this at length). But in truth, this question of the later authorities is itself weak from several angles, and this is not the place to elaborate.