Bava Metzia 37-43
Rav Kahana said, “A person prefers to have one ‘kav’ (a certain measure) of his own produce instead of nine ‘kavim’ that belong to someone else.”
This facet of human nature is one explanation cited on our daf to explain a statement of the Tana Kama in the mishna: “If one gives his fruit to another person for guarding, then even if they begin to rot the guard may not touch (i.e., sell) them.” Rav Kahana reasons that since the owner personally toiled to succeed in bringing his fruit into existence, they are especially dear to him. Therefore, he would prefer havingone measure of them rather than “nine times” as much that came from someone else. (Rashi)
A “measured,” tangential note: The word “kav” is a measure mentioned in the Torah in Melachim II 6:25. It is equal to four “lug” and is somewhat more than a liter in volume. The measure of a “revi’it” that is often mentioned with regard to the size of a kiddush cup, and is the amount of liquid drink requiring an after-blessing, is one-quarter of a lug, or one-sixteenth of a kav.
Bava Metzia 38a