Adam Clarke on 1 Timothy 5:19

Against an elder - Be very cautious of receiving evil reports against those whose business it is to preach to others, and correct their vices. Do not consider an elder as guilty of any alleged crime, unless it be proved by two or three witnesses. This the law of Moses required in respect to all. Among the Romans, a plebeian might be condemned on the deposition of one credible witness; but it required two to convict a senator. The reason of this difference is evident: those whose business it is to correct others will usually have many enemies; great caution, therefore, should be used in admitting accusations against such persons.