Study Guide Chagigah 21 Today’s daf is sponsored by Sam Kunin in honor of Helen Lewis’s birthday “Your incredible dedication to women’s learning, the Jewish community and beyond is a daily inspiration to us all. Thank you for all your guidance kindness and patience. Love, Mim, Nat, Toby and Sam.” Why is one not allowed to immerse a vessel within a vessel for sacrificial items? The first answer given is that it is an issue of chatzitza, a separation between the item and the mikveh waters. If so, then there are two cases in the Mishna that relate to this issue - why would the Mishna find it necessary to list them both? The Gemara offers an explanation. A different answer is brought as well, which explains the issue differently. The concern is that one may put needles or something small into a utensil with a very small opening, which would not be a valid tevila as the opening is too narrow. Therefore they forbade any case of purifying in a mikveh one utensil inside another utensil.