api nah suhrdas tata
drstah sruta va yadavah
sva-puryam sukham asate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My uncle, you must have visited Dvaraka. In that holy place are our friends and well-wishers, the descendants of Yadu, who are always rapt in the service of the Lord Sri Krsna. You might have seen them or heard about them. Are they all living happily in their abodes?
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The particular word krsna-devatah, i.e., those who are always rapt in the service of Lord Krsna, is significant. The Yadavas and the Pandavas, who were always rapt in the thought of the Lord Krsna and His different transcendental activities, were all pure devotees of the Lord like Vidura. Vidura left home in order to devote himself completely to the service of the Lord, but the Pandavas and the Yadavas were always rapt in the thought of Lord Krsna. Thus there is no difference in their pure devotional qualities. Either remaining at home or leaving home, the real qualification of a pure devotee is to become rapt in the thought of Krsna favorably, i.e., knowing well that Lord Krsna is the Absolute Personality of Godhead. Kamsa, Jarasandha, Sisupala and other demons like them were also always rapt in the thought of Lord Krsna, but they were absorbed in a different way, namely unfavorably, or thinking Him to be a powerful man only. Therefore, Kamsa and Sisupala are not on the same level as pure devotees like Vidura, the Pandavas and the Yadavas.
Maharaja Yudhisthira was also always rapt in the thought of Lord Krsna and His associates at Dvaraka. Otherwise he could not have asked all about them from Vidura. Maharaja Yudhisthira was therefore on the same level of devotion as Vidura, although engaged in the state affairs of the kingdom of the world.