From Rigpa Wiki
Shri Bhadra's father served the Buddha's father as a charioteer, and he wished for a son to become Prince Gautama's charioteer. Later, when Gautama became the Buddha, he promised that if he had a son, that son would become a monk. Shri Bhadra was born and grew up to be a renowned scholar, later upon hearing of his father's promise, he gladly became a monk. Accumulating merit and practising with diligence he became an arhat renowned for his teaching and meritorious actions. He lives on an island in the Yamuna River, a tributary of the Ganges, with 1,200 arhats.
His right hand is in the Dharma-teaching mudra which enables the understanding of compassion and emptiness. His left is in the meditation mudra which develops the wisdom of correct discernment of the paths to overcome habitual patterns.
- Crystal Mirror, volume VI, Dharma Publishing 1984