Today's daf is sponsored by Gitta Neufeld in loving memory of her mother-in-law, Alice Neufeld, Aidel bat Natan veSara. "She was the Naomi to my (I hope) Ruth. We were blessed to have Oma live with us when she could no longer live alone - at a feisty 90 - and continue to be blessed as we watch our children and grandchildren follow in her ways of Torah, Yirat Shamayim and Hatzneya Lechet.  Yehi Zichra Baruch." Today's daf is sponsored by Blima Slutsky in loving memory of her sister, Rivka Sara bat Tina and Yitzhak. A debate between Rabbi Yochanan and Reish Lakish is brought regarding one who says to another “I owe you (a certain amount of) money.” If it was in writing, can we assume it is legitimate, even if there are no witnesses signed on the document? Two attempts to support Rabbi Yochanan's position are brought (one from our Mishna), but both are rejected. Rava suggests that perhaps their debate was also a debate between tannaim regarding an arev, a guarantor. But that suggestion is rejected as well. Why are agreements made between the family of the groom and the family of the bride considered as if there were written, even if they were not written? Ravina asks whether these agreements between the families can be written down or not. Rav Ashi answers that they cannot. Three sources are brought (including our Mishna) as difficulties on Rav Ashi but are resolved. Can we derive from our Mishna that the mother usually has precedence for custody over girls, even if they are older?