 The garment in question was a large cloth square, which the poor used for sleeping within, and so the garment was needed to survive the cold nights; if it had been offered as security, this would have put at risk the very life of the debtor.The Deuteronomic verse expresses a similar concern for the security of the debtor's life but rather than prohibiting a particular "garment" from becoming the security for a loan, it prohibits instead the use of a millstone.The millstone was used to make flour, and hence would be required for the manufacture of bread, a staple food among the poor; if the millstone had been offered as security, the debtor would have been at risk of starvation.