Guru Har Rai Ji on the importance of reciting Baani!
One time someone asked Guru Har Rai a question about this. They asked, “Guru ji, may I ask a question?” Of course the Guru lovingly allowed the question, "We always sing so much Gurbani. Sometimes we don't understand what we are singing. Is there any use in singing these holy words when we don't know what they mean?”
Guru ji didn't answer at that moment, he just smiled and waited till he could teach by showing. Rather than just preaching to us, Guru ji always teaches us through experience.
He waited a few days until everyone was riding somewhere together on their horses. Guru ji had them all stop and asked, “Do you see that pot over there?” “Yes, my Guru, that broken pot on the ground? Yes I see it!" “Go bring a piece of the pot.” One of the Sikhs brought a piece of the clay pot over. The pot used to have butter in it, ghee actually. It had been laying in the sun and the ghee had melted into the sides of the pot. The shiny ghee left a streak down the inside of the piece.
Guru ji explained, “This is what happens when we sing Gurbani.” The Sikhs wondered what he meant by that. He continued, “Even when we don't understand Gurbani... when we sing it with devotion... it still sticks to our hearts, just as the ghee stuck to this pot." They began to understand why he had them bring the greasy piece of pot over, "Someday the sunlight of knowledge will come to our minds and then, just like this ghee, it will melt... and the Gurbani in our hearts will turn to wisdom."
Guru ji showed them the great benefit of Gurbani, "Even if we don't understand it, Gurbani is the seed of our liberation.”
Source: http://www.sikhnet.com/stories/audio/guru-har-rai-and-pot