Translation: Oke Tawfeeq Aboo Rushdaa
The great scholar of Andalusia, Muhammad bn Ahmad bn Juzzay Al-Kalbee (d. 741 A.H), may Allah be pleased with him said:
"People differ in their reasons for choosing companions; some choose companions for mutual benefits, and for the favor of friendship for the sake of Allaah. Others prefer reclusion and seclusion because they consider it closer to safety and since the conditions for companionship are hardly met.
People are into three categories:
Friends; these are few.
Acquaintances; these are the most dangerous of people to you; and the one who does not know you and you do not know him; you are safe from him and he is safe from you.
There are seven criteria for choosing a companion:
1. That he is Sunni in creed.
2. That he 'is devout in his religion because if he is an innovator or a transgressor, he may drag his companion into his ways or that people may assume he is like him since man is upon the ways of his companion.
3. That he is wise; since friendship with a fool is a misfortune.
4. That he is of good morals because, with the one with bad morals, one is not free from his enmity.
5. That he has a clear mind (to you) whether you are around or away. He should not be given to rancor, envy, bad intention or hypocrisy.
6. That he is true to his promise not the weak or unfaithful type.
7. That he fulfils your rights as you fulfil his; there is no goodness in such companion who does not reciprocate your dutifulness to him. "
(Al-Qawaaneenul Fiqhiyyah: vol.1, p. 291)