Dhammapada Verses 7 and 8
The Story of Thera Mahakala
Mahakala and his brother Culakala. Mahakala and Culakala were two merchant brothers from the town of Setabya. While travelling about with their merchandise on one occasion, they had a chance to listen to a religious discourse given by the Buddha. After hearing the discourse Mahakala asked the Buddha for admission to the Order of the bhikkhus. Culakala also joined the Order but with the intention of coming out of the Order and to bring out his brother along with him.
Mahakala was serious in his ascetic practice at the cemetery (Sosanika dhutinga) and diligently meditated on decay and impermanence. He finally gained Insight and attained arahatship.