HONOUR TO WHOM HONOUR IS DUE
Yamha dhammam vijaneyya samma sambuddha desitam
Sakkaccam tam namasseyya aggihuttam'va brahmano.
If from anybody one should understand the doctrine preached by the Fully Enlightened One,
devoutly should one revere him, as a brahmin reveres the sacrificial fire. 
The Venerable Sariputta was born of brahmin parents in Upatissa village. That is why he was named Upatissa. His mother was Sari. His very close friend was Kolita, another brahmin youth, son of Moggali. Both the youths were searching for the right doctrine which would lead them to liberation from the round of rebirths, and both of them had a great desire to enter a religious order. First, they went to Sanjaya, but they were not satisfied with his teaching. Then they wandered all over looking for a teacher who would show them the way to the Deathless, but their search was fruitless. After some time, they parted company but with the understanding that the one who found the true Dhamma first should inform the other.
About that time, the Buddha arrived at Rajagaha with a company of bhikkhus, including Venerable Assaji, one of the group of first Five Bhikkhus. While Assaji was on an almsround, Upatissa saw him and was very much impressed by his noble countenance. So Upatissa respectfully approached Assaji and asked who his teacher was, what doctrine his teacher taught, and also briefly to explain the doctrine to him. Assaji then told Upatissa about the arising of the Buddha and about his sojourn at the Veluvana monastery in Rajagaha. He also quoted a short stanza.
Ye dhamma hetuppa bhava tesam hetum tathagato aha
Tesan ca yo nirodho evem vadi maha samano.
('The Tathagata has declared the cause and also the cessation of all phenomena which arise from a cause. This is the doctrine held by the Great Samana').
When the verse was only half uttered, Upatissa comprehended the Dhamma.
As promised, Upatissa went to inform Kolita that he had found the true Dhamma. Then the two friends, accompanied by many followers, went to the Buddha and requested permission to enter the Order. Thus Upatissa and Kolita, together with their followers, were admitted as bhikkhus. Upatissa and Kolita then came to be known as Sariputta and Moggallana respectively. Soon after, Moggallana and Sariputta attained Arahanthood.
The Venerable Sariputta always remembered that he had been able to meet the Buddha and attain the Deathless through Assaji. So, he always paid respects in the direction where his teacher was and he always went to bed with his head in the same direction. Other bhikkhus who were staying with him at the Jetavana monastery misinterpreted his actions and told the Buddha, 'Venerable Sir! Sariputta still worships the various directions, as he had done before as a brahmin youth. It seems as if he has not yet given up his old beliefs.' Sariputta explained that he was only paying respects to his teacher, the Venerable Assaji, and that he was not worshipping the various directions. The Buddha then said, 'Bhikkhus! Sariputta is not worshipping the various directions; he is only paying respects to his teacher who paved the way for him to meet the Buddha. It is right for him to pay homage to such a teacher.'