Can a person who has not realized the first fruit (srotāpanna) introduce and explain the Dharma to others?

Question: Can a person who has not yet attained the first fruit (srotāpanna) introduce and explain the Buddha-dharma to others? 

Answer: As long as one has some understanding of the Buddha-dharma, one can introduce and explain it to others truthfully. However, one should speak only as much as one knows, and not go beyond one's bounds. Do not speak of things you are not sure about; follow the principle of "knowing what you know and admitting what you do not know." At the same time, do not intentionally or unintentionally lead others to believe that you have realized the truth. If you have not attained the fruits, do not teach others how to attain the fruits or how to see the mind, and even less should you presumptuously force upon others confirmations of their realization, thereby misleading them. Speak according to the level of your own cultivation—do not overstep or go beyond your bounds. Honestly tell others your actual level of practice; anything beyond that should serve only as a reference, not as guidance. In this way, there will be no fault. 

There are not a few people who are presumptuous despite lacking cultivation. Such people like to show themselves off and to flaunt themselves, so they often say things beyond their bounds. This is all because of severe grasping at self (ātma-grāha); the "I" in their minds could practically burst them open. The mark of self and the mark of sentient beings are both very firm and hard to break. As a result, they create evil karma such as false speech. In reality, they gain no benefit from it; even if they do, it may not be others' envy and respect—it is merely feeling good about themselves. In this way, sentient beings' afflictions and fetters bind their own minds firmly, and they do not know the taste of liberation—pitiable and lamentable indeed.