Ohalot, Chapter Fifteen, Mishnah Ten
1) One who touches a corpse and touches vessels, one who overshadows a corpse and touches vessels, they [the vessels] are unclean.
2) One who overshadows a corpse and overshadows vessels, one who touches a corpse and overshadows vessels, they [the vessels] are clean.
3) If his hands are a handbreadth wide, they are unclean.
4) Two houses, and in each there is a half an olive’s worth of corpse and he puts one hand into each house:
a) If his hands are a handbreadth wide, he brings uncleanness;
b) But if not, he does not bring uncleanness.
Section one: A person who has become unclean through a corpse, whether by contact or by overshadowing, now defiles vessels by contact (see 1:1-4).
Section two: However, a person who has been defiled by contact with a corpse or by overshadowing a corpse does not defile vessels by overshadowing.
Section three: If one hand is overshadowing or touching a dead body and the other hand is simultaneously overshadowing vessels, it is possible to convey the impurity from the corpse to the vessels, as long as each hand is a handbreadth, such that it can form an ohel. If the hands are smaller than a handbreadth, they do not convey the impurity.
Section four: The mishnah now brings up a similar circumstance where a person can convey impurity if each of his hands is a handbreadth. There are two houses adjacent to one another and their doors or windows are opposite each other. There is less than an olive’s worth of impurity in each house and a person puts his hands into both houses simultaneously. If his hands are each a handbreadth, then they successfully bring the impurity from each into the other, and all vessels found in either house are impure. If his hands are not one handbreadth, then they don’t join the two half olives, and all remains pure.