SHAFAQNA – Imam Ali (AS) said: The Almighty has hidden 4 points in 4 things: Firstly, has hidden Godâ€™s satisfaction in all worships. Therefore, do not count any act of worship as small, maybe Godâ€™s satisfaction is in that and you are not aware of it. Secondly, has hidden Godâ€™s wrath in all sins. Therefore, do not count any sin as small, maybe Godâ€™s anger is in that small sin which you are unaware of. Thirdly, Godâ€™s acceptance of all Duas is hidden. Therefore, do not count any Dua as small, maybe it is accepted and you are not aware of it. Fourthly, God has hidden his friends amongst people. Therefore, do not belittle anyone, maybe that person is the friend of God and you are not aware of that .
 Khesaal, Vol. 1, page 198.