John Gill Commentary Deuteronomy 24:3

"And if the latter husband hate her, and write her a bill of divorcement, and give it in her hand, and send her out of his house; or if the latter husband die, who took her to be his wife;" — Deuteronomy 24:3 (ASV)

And [if] the latter husband hate her
Or less loves her than another woman, and she is disliked by him as she was by her former husband;

and write her a bill off divorcement, and giveth [it] into her hand ,
and sendeth her out of his house :
as he had by this law a permission, in like manner as her former husband had; (See Gill on Deuteronomy 24:1);

or if her latter husband die, which took her [to be] his wife ;
and she survives him; as she is then by death loosed from the law of an husband, she may lawfully marry another man, but not her former husband, as follows.