"I myself will look after and tend my sheep" so declares the Lord on account of the neglect of Israel's leaders. "As a shepherd tends his flock when he finds himself among his scattered sheep, so will I tend my sheep. I will rescue them from every place where they were scattered." In Jesus, this promise was fulfilled. Having seen the vast crowd coming toward him, Jesus' heart was moved to pity "because they were like sheep without a shepherd." Jesus' heart was moved because he had a shepherd's heart. The Sacred Heart is a Shepherd's Heart.
How did he look after his sheep? His heart moved with pity, Jesus began teaching them. At the end of the day, he took bread, gave thanks, broke the bread and distributed it for the people to eat. He tends his flock by the light of his word. He feeds his flock by giving them his Body to eat and his Blood to drink. His Heart, being a Shepherd's Heart, moves him to seek out the lost, to bring back the strayed, to bind up the injured, to heal the sick...to shepherd them rightly.
His love appoints men to be priests so that through them, Jesus might continue feeding and tending his flock. Whenever we see priests, we are reminded of Jesus' love for us. Thus St. John Vianney says: "The priesthood is the love of the Heart of Christ."