Albert Barnes on Titus 2:1

But speak thou. In thine own ministry. In the previous chapter he had given him instructions as to the kind of persons who were to be put into the sacred office. Here he gives him special instructions in regard to his own breaching.

The things which become sound doctrine. To wit, those which he proceeds immediately to specify. On the phrase sound doctrine, 1Timm 1:10, comp. 2Ti 4:3.