It was Yama, who had taken the form of Yaksha. He wanted to see Yudhishthira and test him. He asked several questions to Yudhishthira. Yaksha was astonished at how sharply and without being partial, Yudhishthira answered all his questions correctly. Hence, we can say that Yaksha was pleased by the impartiality of Yudhishthira and granted the life of all his brothers.