4:90

The exception to this is for those who take refuge with your allies or come over to you because their hearts restrain them both from fighting against you and from fighting against their own people. If Allah had wanted, He would have given them power over you and they might easily have fought against you; therefore, if they withdraw from you and cease their hostility and offer you peace, in that case Allah has not granted you permission to fight against them.
Meaning:-
Restrain: prevent, stop, keep, hold back; hinder, impede, hamper, restrict, constrain, obstruct;
Hostility fighting, conflict, armed conflict, combat, warfare, war, bloodshed, violence, action, military action, battles, strife.