Regarding how to reprimand a member of the Sanga, it is said that The Buddha gave the following advice:

'First a brother must be warned (if he be a wrong-doer):

and when he has been duly warned,

 

let him again be reminded:

 

and when he has been reminded,

 

let him be definitely charged with wrong-doing,

 

let some discreet and able brother bring the matter before the Order.

 

 

 

 

 

A brother, Upali, who is about to admonish another must realise within himself five qualities before doing so, (that he may be able to say), thus:

 

"In due season will I speak, not out of season (i.e. at the time).

 

In truth will I speak, not in falsehood.

 

Gently will I speak, not harshly.

 

To his profit will I speak, not to his loss.

 

With kindly intent will I speak, not in anger."

Vinaya, ii.9.