Ezekiel 34 condemns Israel's shepherds and promises that the LORD himself will search for his sheep, while also promising a Davidic shepherd.
Jesus' conduct toward sinners embodies the divine shepherd's seeking activity and prepares for his explicit statement in Luke 19:10.
The Ezekiel background and Jesus' self-interpreting conduct make this strong cumulative YHWH-identification evidence.
Religious critics grumble that Jesus receives sinners; Jesus answers with the parable.