SB 1.13.13

nanv apriyaṁ durviṣahaṁ
nṛṇāṁ svayam upasthitam
nāvedayat sakaruṇo
duḥkhitān draṣṭum akṣamaḥ

nanu—as a matter of fact; apriyam—unpalatable; durviṣaham—unbearable; nṛṇām—of humankind; svayam—in its own way; upasthitam—appearance; na—did not; āvedayat—expressed; sakaruṇaḥ—compassionate; duḥkhitān—distressed; draṣṭum—to see; akṣamaḥ—unable.

Compassionate Mahātmā Vidura could not stand to see the Pāṇḍavas distressed at any time. Therefore he did not disclose this unpalatable and unbearable incident because calamities come of their own accord.

According to Nīti-śāstra (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 Pāṇḍavas, it was almost impossible to disclose an unpalatable piece of news like the annihilation of the Yadu dynasty. Therefore he purposely refrained from it.