It is mentioned in a reliable tradition that one day Musa was sitting when Satan appeared before him wearing a multicolored cap. He took off his cap and approached Musa. Musa asked as to who he was? He said, “Iblis.” Musa said, “May Allah not give residence to anyone near your residence. Why have you donned this cap on your head?” He said, “I attract the children of Adam through these colors.” Musa said, “Tell me the sin which if committed by the son of Adam you overpower him fully.” “When he overestimates his deed and gets vain and then underestimates his sin.”
Then he said, O Musa! Never stay alone with a woman who is not permissible for you. Such people I do not leave to my companions but personally make efforts in misleading them and do not leave his side until he indulges in sin. Also never, give any promise to your God because whoever gives any promise to Allah I do not leave them to my companions but attend personally to him to endeavor that he may not fulfill his promise. And (O Musa)! Whenever you think of giving charity, make haste because whenever one intends to give charity I pay attention to him myself and do not leave him to my assistants. I make maximum efforts to make him regret it.”