(he) divorces her (finally),
they return to each other
they (will be able to) keep
(are) the limits of Allah.
So if a husband divorces his wife (irrevocably), He cannot, after that, re-marry her until after she has married another husband and He has divorced her. In that case there is no blame on either of them if they re-unite, provided they feel that they can keep the limits ordained by Allah. Such are the limits ordained by Allah, which He makes plain to those who understand.
如果他休了她,那末,她以後不可以做他的妻子,直到她嫁给其他的男人。如果後夫又休了她,那末,她再嫁前夫,对於他们俩是毫无罪过的,如果他们俩猜想自己能遵守真主的法度。这是真主的法度,他为有知识的民众而阐明它。