Tradition says Vajra was born in Tumbavana to Sunanda and Dhanagiri, who had left home to become a monk. The baby cried so constantly that his mother handed him to his father when Dhanagiri came for alms, and the child grew up near the nuns, learning scriptures simply by hearing them recited. When Sunanda later asked for him back, the case went to the king; tradition tells that the small boy ignored his mother's toys and sweets and picked up his father's monk's broom.
Initiated by Acharya Simhagiri, his father's guru, Vajra studied the ten Purvas with Bhadragupta at Ujjain and became a renowned teacher. Tradition says that during a severe famine he used his spiritual powers to carry the community to safety. He taught Arya Rakshita, who learned about nine and a half Purvas from him. After Vajraswami, knowledge of the full tenth Purva was lost, and many later Svetambara lineages trace themselves to him through the Vajri shakha.
