[If] he declared to him, “My father is acceptable to me,” [or] “Your father is acceptable to me,” [or] “Three cattle herders are acceptable to me” —- R’ Meir says: He can retract. But the Sages say: He cannot retract. [If] he was under an obligation of oath to another, and he said, “Vow to me by the life of your head,” R’ Meir says: He can retract. The Sages, however, say: He cannot retract.

These are the ones who are disqualified: one who plays dice, one who lends on interest, pigeon-flyers, and shevi-is-merchants. Said R’ Shimon: Originally they called them sheviis-stockpilers. When the oppressors increased they changed to calling them sheviis-merchants. Said R’ Yehudah: When? When they have no other trade, but if they have another trade, they are qualified.