Four Great Standards. Before he passed away, the Buddha gave us practical advice to assess situations in which we hear a monk proclaiming that what he teaches "is the Dhamma... the Vinaya... the teachings of the Master". He may say that he heard and learned it in the presence of
* the Buddha himself,
* a Sangha in a certain monastery with its theras (elders) and leaders,
* many learned theras in a certain monastery who are holders of the traditional teachings, bearers of the Dhamma, Vinaya, and the summaries, or
* a learned thera in a certain monastery who is a holder of the traditional teachings, bearer of the Dhamma, Vinaya, and the summaries.
In such situations, without rejoicing in or scorning the monk's words, we should investigate to see if such teachings are included in the suttas or seen in the Vinaya. If they are, we may conclude that they are the words of the Buddha and that they have been well learned by the speaker. Otherwise, we may conclude that they are not the words of the Buddha and that they have been wrongly learned by the speaker, and so we should reject them.

(Extracted from the MahaPariNibbana Sutta, summarised & translated by Aggacitta Bhikkhu)