Albert Barnes on Matthew 18:11

For the Son of man, etc. This is a second reason why we should not despise Christians, for the Son of man came to seek and save them. He came in search of them when lost; he found them; he saved them. It was the great object of his life; and though obscure and little in the eye of the world, yet that cannot be worthy of contempt which the Son of God sought by his toils and his death.

Son of man. Mt 8:19,20.

That which was lost. Property is lost when it is consumed, mislaid, etc.--when we have no longer the use of it. Friends are lost when they die--we enjoy their society no longer. A wicked and profligate man is said to be lost to virtue and happiness. He is useless to society. So all men are lost. They are wicked, miserable wanderers from God. They are lost to piety, to happiness, and heaven. These Jesus came to save by giving his own life a ransom, and shedding his own blood that they might be recovered and saved.

(h) "save that" Mt 1:21, Lk 9:56, 19:10, Jn 3:17, 10:10, 12:47 1Timm 1:15