This story is after the passing of Ramanujacharya’s spiritual master, Sri Yamunacharya. Yamunacharya had left instructions for Ramanuja to learn a secret mantra from another spiritual master, Sri Nambi.

Ramanuja visited Sri Nambi. Sri Nambi was a strict disciplinarian and a demanding master. He refused to part with the mantra. Ramanuja traveled to visit him 18 times and patiently waited upon Sri Nambi. 

Looking at Ramanuja’s dedication, Sri Nambi agreed to initiate Ramanuja with the mantra. He did so with promises of secrecy. He said, “Ramanuja! Keep this mantra a secret. This is a powerful Mantra of Om Namo Narayana. Those who repeat this mantra will attain salvation. Give it only to disciples who are worthy. If you break this promise, you will suffer in hell.”

The young Ramanuja, after learning this secret mantra, ran to a temple and shouted the mantra at the top of his voice. 

His Guru Sri Nambi became furious and called for Ramanuja. Ramanuja explained, “O beloved master, please prescribe a suitable punishment for my wrong action. I will gladly accept the tortures of hell if millions can attain salvation with this mantra.”

Sri Nambi was very pleased with Ramanuja’s kindness and compassion. He embraced him tightly and blessed him.