Abu Bakr ibn al-‘Arabi said:
Covenants are of two types: one for which expiation may be offered and another for which there is no expiation. That for which expiation may be offered is that which is intended as a vow to refrain from doing something or to do something.
The second type is a covenant in which the two parties are bound in a manner that is permissible according to sharee’ah, and is binding, either exclusively between them or amongst many people. It is not permissible to nullify or abolish such a covenant, and it is not subject to kafaarah (expiation). This is the covenant for which the one who breaks it will be gathered (on the Day of Resurrection) as a betrayer, and a banner will be set up for him commensurate with the degree of his betrayal, and it will be said, “This is the betrayer of So and so.” Maalik says, a covenant sworn by oath is not permitted to be nullified, and this is what is meant by the aayah (interpretation of the meaning):
“and break not the oaths after you have confirmed them — and indeed you have appointed Allaah your surety” [al-Nahl 16:91]
And this is a matter concerning which there is no scholarly dispute.