24:6 One must not take either lower or upper millstones as security on a loan, for that is like taking a life itself as security. 2
1 sn The blood is life itself. This is a figure of speech (metonymy) in which the cause or means (the blood) stands for the result or effect (life). That is, life depends upon the existence and circulation of blood, a truth known empirically but not scientifically tested and proved until the 17th century
2 sn Taking millstones as security on a loan would amount to taking the owner’s own life in pledge, since the millstones were the owner’s means of earning a living and supporting his family.