Study Guide Bava Kamma 64 Today's daf is sponsored by Lisa Malik & Adi Wyner in honor of the birth of their first grandchild, Azriel David son of Ariel and Sofia. "Azi was named in memory of Sofia's great-grandmother, Alexina, and Ariel’s grandfather, David Malik z"l. Our grandson’s name is also a tribute to R. Azriel David Fastag, who composed the "Ani Maamin" melody on a train to Treblinka."  Today's daf is sponsored by Harriet Hartman in loving memory of her grandson Ephraim Yachman. "He learned Daf Yomi daily in the army (+Rashi and Tosafot), even in his "namer." From what verse and how can we derive that a thief pays double for stealing movable items with inherent monetary value? The Gemara brings a braita from the school of Chizkiya to explain the source. After a difficulty is raised against the braita, Rava brings an alternative explanation of the braita. In Rava's version, the braita ends with a difficulty: What are the words "im himatzei timatzei" needed for? The Gemara answers this question by explaining that those words stand as the basis of a klal, prat u'klal drasha from which we derive the application of the basic law of double payment to movable items with inherent monetary value. However, this is rejected as well and instead a riboi, miut, riboi drasha is employed, using the same words. A different braita derives double payment from a different verse - according to that version, what is derived from the words "im himatzei timatzei"?