A man named Nārada is cursed that he can never stay in one place.
Eventually in his wanderings, he comes upon a huge cave in the Himalayas beside the  Ganges river.
The sight of the beautiful mountain, the river and the woods causes Nārada to feel such deep devotion for Ram that the very thought of Ram destroys the curse upon him.
Narada becomes so pure that he attains Samādhi.

Seeing Narada's holiness, the god Indra fears that Narada may be after his kingdom.
He asks Kamadeva, god of desire, to break Narada's Samādhi.
Kamadeva fails in this task, and Narada becomes arrogant over his victory.

When Ram came learns that the seed of a powerful tree of vanity has germinated, then he vows to uproot it immediately.
He creates a town even more beautiful than his own abode, and there he takes the form of Vishwamohini, the beautiful princess of the town, who is seeking a husband.
Kings come from far and wide as suitors, and of course so did Narada went to that town.
When Narada beholds Vishwamohini's beauty, the sage forgets his Vairagya and cannot take his eyes off her.
The sage resolved to marry the princess.
He prayed to Ram and asked for his help in winning "the girl" over: — "O Lord!
Please give me your appearance as there is no other way I can get that princess.
O Lord!
Whatever is beneficial to me, please do that quickly.
I am your devotee."
Pleased that his Maya had worked so well, Ram responds— "O Narada!
Listen, whatever is the best for you, I will do only that, nothing else.
My word is never untrue.
O Yogi Rishi!
Listen, if a patient distraught with disease asks for a poison the doctor does not prescribe it.
Likewise I've resolved to help you."

Narada immediately travels to where the Swayamvara is taking place.
He did not realize that Ram had given him, for his own good, a very hideous form.
Seeing his monkey-like face and terrible body, the princess ignored him completely.
The princess chooses another king (actually Ram in disguise) to be her husband.
Two Jaya and Vijaya who had also assembled there disguised as ridiculed Narada, telling him to look in a mirror.
When Nārada learns he had been tricked, he becomes furious and curses them, and then curses Ram himself, that since Ram took away his love, that someday Ram's love should be taken away; and that since Ram gave him a monkey-like form, that some day only monkeys would help him.

Respecting the curse, Ram removes the Maya of the princess.
Realizing his error, the sage begs for mercy.
Ram tells him to chant Shiva Sahasranama.
To the two gatekeepers who had taunted Narada earlier, Ram tells them that in another time, in the guise of a human, he will slay them and they will attain Moksha.
A man named Nārada is cursed that he can never stay in one place. Eventually in his wanderings, he comes upon a huge cave in the Himalayas beside the  Ganges river. The sight of the beautiful mountain, the river and the woods causes Nārada to feel such deep devotion for Ram that the very thought of Ram destroys the curse upon him. Narada becomes so pure that he attains Samādhi.
Seeing Narada's holiness, the god Indra fears that Narada may be after his kingdom. He asks Kamadeva, god of desire, to break Narada's Samādhi. Kamadeva fails in this task, and Narada becomes arrogant over his victory.
When Ram came learns that the seed of a powerful tree of vanity has germinated, then he vows to uproot it immediately. He creates a town even more beautiful than his own abode, and there he takes the form of Vishwamohini, the beautiful princess of the town, who is seeking a husband. Kings come from far and wide as suitors, and of course so did Narada went to that town. When Narada beholds Vishwamohini's beauty, the sage forgets his Vairagya and cannot take his eyes off her. The sage resolved to marry the princess. He prayed to Ram and asked for his help in winning "the girl" over: — "O Lord! Please give me your appearance as there is no other way I can get that princess. O Lord! Whatever is beneficial to me, please do that quickly. I am your devotee." Pleased that his Maya had worked so well, Ram responds— "O Narada! Listen, whatever is the best for you, I will do only that, nothing else. My word is never untrue. O Yogi Rishi! Listen, if a patient distraught with disease asks for a poison the doctor does not prescribe it. Likewise I've resolved to help you."
Narada immediately travels to where the Swayamvara is taking place. He did not realize that Ram had given him, for his own good, a very hideous form. Seeing his monkey-like face and terrible body, the princess ignored him completely. The princess chooses another king (actually Ram in disguise) to be her husband. Two Jaya and Vijaya who had also assembled there disguised as ridiculed Narada, telling him to look in a mirror. When Nārada learns he had been tricked, he becomes furious and curses them, and then curses Ram himself, that since Ram took away his love, that someday Ram's love should be taken away; and that since Ram gave him a monkey-like form, that some day only monkeys would help him.
Respecting the curse, Ram removes the Maya of the princess. Realizing his error, the sage begs for mercy. Ram tells him to chant Shiva Sahasranama. To the two gatekeepers who had taunted Narada earlier, Ram tells them that in another time, in the guise of a human, he will slay them and they will attain Moksha.
Reasons for Ram avatar