Mbh 1.169.2a

“The Brahmana continued, ‘King Drupada (after this), distressed at heart, wandered among many asylums of Brahmanas in search of superior Brahmanas well-skilled in sacrificial rites. Overwhelmed with grief and eagerly yearning for children, the king always said, ‘Oh, I have no offspring surpassing all in accomplishments.’ And the monarch, from great despondency, always said ‘Oh, fie on those children that I have and on my relatives!’ And ever thinking of revenging himself on Drona, the monarch sighed incessantly. And that best of kings, O Bharata, even after much deliberation, saw no way of overcoming, by his Kshatriya might, the prowess and discipline and training and accomplishment of Drona. Wandering along the banks of the Yamuna and the Ganga, the monarch once came upon a sacred asylum of Brahmanas. There was in that asylum no Brahmana who was not a Snataka, no one who was not of rigid vows, and none who was not virtuous to a high degree. And the king saw there two Brahmana sages named Yaja and Upayaja, both of rigid vows and souls under complete control and belonging to the most superior order. They were both devoted to the study of the ancient institutes and sprung from the race of Kasyapa. And those best of Brahmanas were well-able to help the king in the attainment of his object. The king then, with great assiduity and singleness of purpose, began to court this pair of excellent Brahmanas. Ascertaining the superior accomplishments of the younger of the two the king courted in private Upayaja of rigid vows, by the offer of every desirable acquisition.