John Gill - Exposition
John Gill
A brother offended [is harder to be won] than a strong city,.... A fortified city may sooner be taken by an enemy, than one brother offended can be reconciled to another; their resentments against each other are keener than against another person that has offended them; and their love being turned into hatred, it is more bitter; and it is more difficult to compose differences between brethren...