Each master has three wishes, and cannot exceed this amount by wishing for more wishes. Alternatively, it could mean that while he can revive a person's corpse, he cannot bring them back properly. It is possible, however, that he can do the third one, but as he puts it, 'It's not a pretty picture.
He is also bound by three laws he cannot kill anyone, he cannot make people fall in love with each other, and he cannot revive the dead. Though he possesses 'phenomenal cosmic powers', he is bound to an 'itty bitty living space' and can only use his powers when the owner of the lamp (his master) makes a wish he occasionally does things without granting a wish, but never anything that greatly affects the world around him. Genie was originally a slave imprisoned within his lamp, which, itself, was sealed away in the Cave of Wonders for 10,000 years.
Being a Genie, he was created from the smokeless fire, along with the Angels by God at the beginning of time.