How should we repeat the mantra?

When the sage Narada asked Brahma the creator. "What is the secret of repeating the mantra?" Brahma replied, "The secret is to repeat it with great faith and love".

Once there was a sadhu who lived on the bank of a river. Nearby lived a milkmaid to whom he had given the mantra. Every day, with great devotion she would bring milk to the sadhu. One day, during the rainy season, the river flooded. The milkmaid stood on the bank of the river, wondering how she could take the milk to her Guru. Then she remembered, "When my Guruji gave me the mantra he said, You can go across the ocean of existence by repeating this mantra. this is only a river. So she closed her eyes, repeated the mantra with great faith , and walked across the water to the other shore. The Guru was in his room. She knocked on the door and called, "Baba, open the door ! I have brought milk for you."

"How did you get here?" He asked.

"Don't you know ? When you gave me the mantra you said that if I repeated it, I would go across the ocean . This was just a small stream"

When he heard this, the sadhu became swollen with pride. " What a state I must have attained, if even my milkmaid can walk on water with my mantra !" he though. A few days later, he had to go to town . Once again the river was flooded. He stood on the bank wondering what to do. Then he remembered proudly, " Because of my mantra, the milkmaid crossed the river. Now is the time for me to prove my power. I will use my own mantra to cross the river". So swollen with pride, he took a plunge into the river. He sank like a stone. He could not even ask for help.