The Prophet (saws) said that once, when Musa b. Imran (a) was seated, Iblis approached him with a hooded cloak of motley colors. As he came nearer, he removed the cloak and greeted Musa.
Musa said:"Who are you?"
He said:"I am Iblis."
Musa said:"May Allah not bring your abode closer (to anyone)! Why have you come?"
He said:"I have come to greet you for the status that you have before Allah, Most High."
So Musa said:"And what about this cloak?"
He said:"With that, I hijack the hearts of the people!"
Then Musa asked him:"Tell me about the sin which when Adam's son commits it, you overpower him and get the better of him?"
He said:"When he becomes conceited, and regards his good deeds as too many, and when his own sins seem small to him."
Then he told Musa:"I give you three pieces of advice. Oh Musa, never be alone with a stranger woman or allow her to be with you in privacy, for either of you do not meet the other without me being in your company, without my other colleagues! And be careful when you give a covenant or pledge to Allah! (Fulfill it immediately). For whenever a man pledges a vow or a covenant with Allah, I intervene between him and its fulfillment - without my colleagues! And when you intend giving a charity, give it soon, for when a servant of Allah intends giving alms, I alone, without my colleagues, sit in between his intention and the charity, preventing it!"
Then Iblis turned away saying:"Oh, what a shame, what a grief! I have taught Musa (a secret) which he will impart to the sons of Adam!"