SuttaCentral
I remember reading a sutta in which the Buddha explains a Nun that any teaching that takes one towards renunciation and dispassion is going to be Dhamma teachings, anything otherwise would not be… something like that. Basically the Nun was asking that many people would come and tell this is Buddha’s teachings, how should one be able to judge whether it actually is or not.
Forgive me I could be wrong. Please could someone help with the source of this…
Thanks
AN 8.53:
Gotamī, you might know that certain things lead to passion, not dispassion; to yoking, not to unyoking; to accumulation, not dispersal; to more desires, not fewer; to lack of contentment, not contentment; to crowding, not seclusion; to laziness, not energy; to being burdensome, not being unburdensome. Categorically, you should remember these things as not the teaching, not the training, and not the Teacher’s instructions.
You might know that certain things lead to dispassion, not passion; to unyoking, not to yoking; to dispersal, not accumulation; to fewer desires, not more; to contentment, not lack of contentment; to seclusion, not crowding; to energy, not laziness; to being unburdensome, not being burdensome. Categorically, you should remember these things as the teaching, the training, and the Teacher’s instructions.
AN 7.83:
Upāli, you might know that certain things don’t lead solely to disillusionment, dispassion, cessation, peace, insight, awakening, and extinguishment. Categorically, you should remember these things as not the teaching, not the training, and not the Teacher’s instructions. You might know that certain things do lead solely to disillusionment, dispassion, cessation, peace, insight, awakening, and extinguishment. Categorically, you should remember these things as the teaching, the training, and the Teacher’s instructions.
Thank you so much 
This is exactly what I was looking out for. Grateful