Mahabharata 3.239.16

3.239.16

darbhaprastaramāstīrya niścayāddhṛtarāṣṭrajaḥ |
saṃspṛśyāpaḥ śucirbhūtvā bhūtalaṃ samupāśritaḥ || 16 ||

Vaisampayana continued, "Though addressed in all manner of ways by his friends and counsellors and brothers and relatives, the king wavered not from his purpose. And the son of Dhritarashtra in accordance with his purpose spread Kusa grass on the earth, and purifying himself by touching water, sat down upon that spot. And clad in rags and Kusa grass he set himself to observe the highest vow. And stopping all speech, that tiger among kings, moved by the desire of going to heaven, began to pray and worship internally suspending all external intercourse.