Bava Metzia 75a - 75b
Commodity loans \u2022 Permitted pseudo-interest loans between Torah scholars \u2022 Pseudo-interest loans between family members can lead to usury \u2022 One may not pay interest even with mere words \u2022 To avoid stumbling, witnesses and documentation of a loan protect both lender and borrower \u2022 Remaining in a locale with sustained hardships instead of moving away is tantamount to self inflicted suffering