Eruvin 31A

מערבין לכהן טהור בתרומה טהורה בקבר, היכי אזיל? בשידה תיבה ומגדל.

One may establish an eiruv for a priest who is ritually pure with teruma that is ritually pure and resting on a grave, even though the location is impure and he cannot reach it. How does he go there? In a carriage, crate, or cupboard, which shield him from the ritual impurity.

והא כיון דאחתא איטמיא לה! בשלא הוכשרה, או שנילושה במי פירות.

The Talmud asks: Isn’t it true that once the eiruv was placed directly on the grave, the teruma became defiled, and ritually impure teruma is not fit to be eaten by anyone? The Talmud answers: We are dealing here with a case where the teruma had not yet been rendered susceptible to ritual impurity, as it had not yet come into contact with a liquid. Produce that has yet to come into contact with a liquid does not contract impurity. Or we are dealing with bread that was kneaded with fruit juice, which is not one of the 7 liquids that render a food susceptible to ritual impurity.

והיכי מייתי לה? בפשוטי כלי עץ דלא מקבלי טומאה.

The Talmud now asks: How can he bring it from where it is resting on the grave in order to eat it? The Talmud answers: With flat wooden utensils that are not shaped as receptacles and therefore do not contract ritual impurity.

והא קא מאהיל?! דמייתי לה אחוריה.

The Talmud asks: Doesn’t the utensil cover the grave? The rabbis decreed that anyone who holds a utensil that is a handbreadth wide over a corpse or grave is ritually impure. The Talmud answers: He may bring it on the edge of the utensil while holding the utensil sideways so that it does not form a cover that is a handbreadth wide over the grave.