Study Guide Bava Kamma 66 Today's daf is sponsored by the Hadran Zoom family in loving memory of Sgt. Ephraim ben haRav Shmuel v'Liat, HYD, Ephraim Yachman, son of Liat and Sammy, and grandson of our friend and fellow learner Harriet Hartman. "Even as he fought valiantly to defend Am Yisrael and Eretz Yisrael, his sincerity, commitment to Ahavat Yisrael and Torat Yisrael, and devotion to family and friends shone through as they did throughout his life. May Hashem comfort and give strength to his entire family. Yehi zichro baruch." Rabbi Il'ah and Rabbi Chanina disagreed about an animal that was stolen while still a calf and at the time of judgment was fully grown - is there a requirement to pay four or five times the animal? However, they both seem to agree that the double payment is assessed by its value at the time of the theft. Rav, however, held that the double payment is assessed based on its value at the time of judgment. How can these two approaches be reconciled? Rabba states that both from the Torah and a Mishna we learn that a thief who changes an item after stealing it, acquires the item and is only required to return the value of the item at the time it was stolen. But Rabba and Rav Yosef disagree regarding yei'ush, if the owner despairs of receiving the stolen item back, does the thief acquire it? Two sources are brought as difficulties against Rabba's position and one against Rav Yosef's. All are resolved.