Srimad Bhagavatam Canto 01, Chapter 13, Text 13

SB 1.13.13

nanv apriyam durvisaham
nrnam svayam upasthitam
navedayat sakaruno
duhkhitan drastum aksamah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Compassionate Mahatma Vidura could not stand to see the Pandavas distressed at any time. Therefore he did not disclose this unpalatable and unbearable incident because calamities come of their own accord.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
According to Niti-sastra (civic laws) one should not speak an unpalatable truth to cause distress to others. Distress comes upon us in its own way by the laws of nature, so one should not aggravate it by propaganda. For a compassionate soul like Vidura, especially in his dealings with the beloved Pandavas, it was almost impossible to disclose an unpalatable piece of news like the annihilation of the Yadu dynasty. Therefore he purposely refrained from it.
 
Srimad Bhagavatam Canto 01, Chapter 13, Text 12
Srimad Bhagavatam Canto 01, Chapter 13, Text 14