Ezekiel 33:11 "For thus says the Lord GOD: Behold, I, I myself will search for my sheep and will seek them out.
12 As a shepherd seeks out his flock when he is among his sheep that have been scattered, so will I seek out my sheep, and I will rescue them from all places where they have been scattered on a day of clouds and thick darkness.
13 And I will bring them out from the peoples and gather them from the countries, and will bring them into their own land. And I will feed them on the mountains of Israel, by the ravines, and in all the inhabited places of the country.
14 I will feed them with good pasture, and on the mountain heights of Israel shall be their grazing land. There they shall lie down in good grazing land, and on rich pasture they shall feed on the mountains of Israel.
15 I myself will be the shepherd of my sheep, and I myself will make them lie down, declares the Lord GOD.
16 I will seek the lost, and I will bring back the strayed, and I will bind up the injured, and I will strengthen the weak, and the fat and the strong I will destroy. I will feed them in justice.
The priests of Israel utterly failed. They succumbed to idolatry. They became wolves rather than shepherds. God condemned them for this. And he promised to become the shepherd of his people. God fulfilled this promise in Christ, as he did all Old Testament promises.
The promise was two fold: God would become the shepherd and he would seek his sheep. Jesus fulfilled both parts. He was the shepherd of his sheep and he sought and seeks sheep for his flock.
Jesus said "I am the good shepherd". (John 10:11, 14) He calls sheep into his fold, they know him and follow him. And, Jesus came to seek his sheep. He said "...the Son of Man came to seek and save the lost."