From Nagarjuna's Treatise on the Great Perfection of Wisdom
Question: What is meant by the giving of Dharma?
Response: There are those who say that the giving of Dharma consists in being of benefit through the constant use of fine words. Then again there are those people who say that the giving of Dharma consists in proclaiming for people the marvelously good dharmas from the discourses of the Buddhas.
Yet again, there are those people who say that the giving of Dharma consists in using three kinds of Dharma to teach people: 1) sutra; 2) vinaya; and 3) abhidharma.
Then again, there are those people who say that the giving of Dharma consists in employing four kinds of Dharma treasuries to teach people: First, the sutra treasury; second, the vinaya treasury; third, the abhidharma treasury; and fourth, the "various topics" treasury.
Additionally, there are people who say that, generally speaking, the giving of Dharma consists in employing two kinds of Dharma to teach people: 1) the Dharma of the Hearers; and 2) the Dharma of the Mahayana.
Question: Individuals such as Devadatta, Hatthaka and others also employed the three treasuries, the four treasuries, the Dharma of the hearers, and the Dharma of the Mahayana to teach people and yet they themselves [fell] into the hells. Why did this situation develop?
Response: Devadatta was possessed of many offenses arising from erroneous views. Hatthaka was possessed of many offenses arising from false speech. It is not the case that this was pure giving done for the sake of the Way. It was done solely for the sake of seeking fame, self-benefit, reverence and offerings. On account of the offenses created by his unwholesome mind Devadatta entered the hells while still alive. When Hatthaka died he fell into the wretched destinies.
Moreover, the giving of Dharma does not consist solely in words and speech. The giving of Dharma consists in constantly employing a pure mind and wholesome thoughts in the offering of instruction to everyone. Just as it is with the giving of material gifts where there is no measure of blessings or virtue associated with it if one fails to maintain a wholesome mind, so too it is with the giving of Dharma. If one fails to maintain a pure mind and wholesome thoughts, then it is not the case that this constitutes the giving of Dharma.
Then again, if the speaker of Dharma is able to maintain a pure mind and wholesome thought as he praises the Three Jewels, opens the door to understanding offenses and blessings, explains the four truths, and so goes about teaching and transforming beings so that they are caused to enter the buddha way, this constitutes true and pure Dharma giving.
Looked at another way, generally speaking, Dharma is of two kinds. The first consists in not tormenting beings while also maintaining a wholesome mind, loving-kindness and sympathy. This constitutes the causal basis for the buddha way. The second consists in contemplating and realizing that all dharmas are truly empty. This constitutes the causal basis for the way of nirvana. If, in the midst of the great assembly one lets flourish a deeply compassionate mind as one sets forth these two types of Dharma, and if in doing so it is not for the sake of garnering fame, offerings or expressions of reverence, this constitutes pure Dharma giving rooted in the buddha way.