"Nor share in others' sins," that is, in the sins of the one ordained, "by raising an unworthy man to the rank of minister of mysteries for the people" (Oecumenius). If you quickly ordain someone without proper inquiry, it may happen that he proves unsound. The sins he later commits, and the harm he thereby causes the Church, will be imputed to you. You will be a participant in others' sins. "Having given him authority, you will undergo punishment for the sins he has committed, both former and future. For by untimely remitting his former sins, you will become guilty also of those he commits afterward. You will be the cause of the latter, because you entrusted him with authority. You will be guilty of the former, because you did not allow him to mourn them and come to a state of compunction. You become a sharer both in his good works and in his sins" (St. Chrysostom). "One must not ordain a man under suspicion of sins, whose purity is doubtful, lest the ordainer be stained by his sins. If his sins are completely hidden and no trace of them is visible, the ordainer is safe and his conscience is free. But suspicion must inspire fear. He sins if he ordains without proper testing. The one ordained must be better than the rest. It is not enough for him to be without reproach. His good works must be manifest, so that he may be judged worthy of ordination" (Ambrosiaster).
"Keep yourself pure." According to the course of the speech, it is more direct to understand "pure" as free from the imputation of the sins of the one ordained. Thus blessed Theodoret says: "Do not make yourself liable to condemnation," that is, by ordaining incautiously a man who was unworthy and whose sins will stain you yourself. Ambrosiaster speaks in the same way: "By keeping this, that is, by strict inquiry and assurance of the worthiness of the one ordained, the bishop will preserve himself pure in relation to the faith and the Church. In the age to come he will receive a recompense for it." But our other interpreters understand here a commandment to St. Timothy to guard his own moral purity. St. Chrysostom says: "Here the Apostle speaks of continence." Oecumenius and Theophylact write: "He gives a lesson concerning chastity. He exhorts him to guard chastity." The connection with what precedes would then be this: while discerning whether others are worthy of ordination, see that you do not lose your own dignity. Or thus: so that you may more boldly examine whether this man is good or that one bad, be pure yourself. Or again: if you preserve yourself pure, you will have eyes to see whether another is pure and worthy. St. Chrysostom adds this reflection: "If the Apostle commands continence to a man who kept fasts to such a degree, and used water for so long, that he began to suffer illnesses and frequent infirmities. And that man is not offended by his admonitions, then much more should we not be offended when we hear anyone's instructions on this matter." If we accept this thought, we may see in it the reason or occasion for the reminder that follows.