Theophylact of Ohrid

In the words "and when the Chief Shepherd appears," the conjunction "and" is put in place of "so that," that is, so that when the Chief Shepherd appears, you may receive the crown of incorruption.

Commentary on 1 Peter ↗

Oecumenius

Furthermore, when it is said, "And when the chief Shepherd appears," it is a conjunction. And it is informally placed for "So that": that is, "So that when the Chief Shepherd appears, you will receive the unfading crown of glory." Just as in Psalm 89, when it is said, "And look upon your servants and upon your works." For there "And" is placed in the place of "Because of which."

Commentary on 1 Peter ↗

Methodius of Olympus

But let us, beloved, return in our discourse to that point whence we digressed, exclaiming, Blessed is He that cometh in the name of the Lord: that good and kind Shepherd, voluntarily to lay down His life for His sheep. That just as hunters take by a sheep the wolves that devour sheep, even so the Chief Shepherd,

Methodius Oration on the Psalms ↗

Augustine of Hippo

While thinking of himself as a martyr to be, Cyprian did not allow himself to forget that he was still a bishop and was more anxious about the account he was to give to the chief shepherd concerning the sheep committed to him than he was about the answer he would give to the unbelieving proconsul, concerning his own faith.

Sermons 309.4 ↗