Full Idea
If you fear treachery from any of your allies, you may retaliate by breaking off your treaty with them; Allah does not love the treacherous.
Gist of Idea
You may break off a treaty if you fear treachery from your ally
Source
Mohammed (The Koran [c.622], Ch.8)
Book Reference
Mohammed: 'The Koran', ed/tr. Dawood,N.J. [Penguin 1968], p.311
A Reaction
I do not think this is good advice. Everybody fears treachery, but if we all acted on that fear human relationships and society would immediately collapse. If anyone thought this was good advice, I would not want to make a treaty with them.