Threefold kindness

Threefold kindness (Wyl. bka' drin gsum ldan) of the root teacher:

In the Sutrayana

According to the Great Tibetan-English Dictionary:

1. Transmitting the vows (or precepts)
2. Giving oral transmissions
3. Granting instructions

According to Dungkar Lobzang Trinlé's Great Dictionary:

1. Teaching the Dharma
2. Blessing the mind of the disciple
3. Sustaining the assembly through material support

In the Vajrayana

1. Conferring empowerment (sngags kyi dbang bskur)
2. Explaining the tantras (rgyud bshad)
3. Granting pith instructions (man ngag gnang)

In addition, Dungkar's Great Dictionary says that the expression refers to the transmission of the three sets of vows, i.e.

1. Pratimoksha precepts
2. Bodhisattva vows
3. Tantric samayas

Source

RigpaWiki:Threefold kindness