Moses
Deuteronomy 24:4ESV·traditional attribution

then her former husband, who sent her away, may not take her again to be his wife, after she has been defiled, for that is an abomination before the LORD. And you shall not bring sin upon the land that the LORD your God is giving you for an inheritance.

Matthew Henry Presbyterian @wholebiblehenry

This is that permission which the Pharisees erroneously referred to as a precept, Mat 19:7, Moses commanded to give a writing of divorcement. It was not so; our Saviour told them that he only suffered it because of the hardness of their hearts, lest, if they had not had liberty to divorce their wives, they should have ruled them with rigour, and it may be...

Commenting on Deuteronomy 24:1-4

John Gill Reformed Baptist @doctorgill

Her former husband which sent her away may not take her again to be his wife,.... Though ever so desirous of it, and having heartily repented that he had put her away: this is the punishment of his fickleness and inconstancy, and was ordered to make men cautious how they put away their wives; since when they had so done, and they had been married...

Geneva Bible Notes Reformed @genevanotes

Her former husband, which sent her away, may not take her again to be his wife, after that she is defiled; for that [is] abomination before the LORD: and thou shalt not cause the land to sin, which the LORD thy God giveth thee [for] an inheritance. (b) Seeing that by divorcing her he judged her to be unclean and defiled.