Srimad Bhagavatam Canto 03, Chapter 07, Text 36

SB 3.7.36

anuvratanam sisyanam
 putranam ca dvijottama
anaprstam api bruyur
 guravo dina-vatsalah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
O best among the brahmanas, those who are spiritual masters are very kind to the needy. They are always kind to their followers, disciples and sons, and without being asked by them, the spiritual master describes all that is knowledge.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
There are many subjects to be known from the bona fide spiritual master. The followers, disciples and sons are all on one level for the bona fide spiritual master, and he is always kind to them and always speaks to them on transcendental subjects, even though he is not asked by them. That is the nature of the bona fide spiritual master. Vidura appealed to Maitreya Muni to speak on subjects about which he might not have asked.
Srimad Bhagavatam Canto 03, Chapter 07, Text 35
Srimad Bhagavatam Canto 03, Chapter 07, Text 37