Study Guide Eruvin 31 Today's daf is sponsored by Judy Shapiro for the 7th yahrzeit of her mother Deera Tychman z"l. The gemara brings another law of Rabbi Yehuda regarding a priest setting up an eruv in a cemetery – this time by putting pure truma on a grave. How is this even possible – the gemara raises several potential problems and resolves them. The gemara raises three possible ways to understand the root of the debate between Rabbi Yehuda and the rabbis on this issue. How does the concept of “mitzvot were not given for benefit” factor in? Can one use demai produce or other produce that was the maaser rishon that the levite did or did not separate truma from or maaser sheni or hekdesh that was or was not redeemed. What is the unique aspect of each of these and why were they mentioned in the mishna? Can one give one’s food to a minor, deaf-mute or cognitively limited person? What about someone who doesn’t believe in eruv? How do the laws differ from eruv chatzerot? One can send the eruv with one of those people to give to someone else to put down. How can we be sure it will get there?