Deuteronomy 24:6

Ver. 6. No man shall take the nether or the upper millstone to pledge— This law is of the same merciful kind with that in Exo 22:26-27 which is repeated in the following verses; and it is founded upon the same equitable and compassionate reasons. On the same account it was, that at Rome they were forbidden to take the oxen or plough of a labourer, for the payment of his debts; and there is the same humane provision in our laws also, which prohibit the distraining of a labouring man's working tools or implements. See Blackstone's Commentaries, Book 3: ch. 1.