Do not tell a friend anything you would conceal from an enemy. (Arab Proverb)
At the narrow passage there is no brother and no friend. (Arab Proverb)
A foolish man may be known by six things: Anger without cause, speech without profit, change without progress, inquiry without object, putting trust in a stranger, and mistaking foes for friends. (Arab Proverb)
Without the companionship even paradise would be boring. (Arab Proverb)