"He saw a man" as He was going along, sounds as if Jesus' discovery of Matthew was accidental but nothing that Jesus did was accidental. He surely planned it thus. By the way, the parallels to this account are found at Mark 2:13-17 and Luke 5:27-32.
"Sitting" indicates that Matthew was busy at his work. Mark and Luke call him "Levi," perhaps the name given at his circumcision. Very likely the name "Matthew" (the gift of the Lord) was adopted by him when Jesus called him. It is significant that at Matthew 10:3 Matthew calls himself "publican."The Jews detested the publicans because
These three in addition to the fact that no one likes to pay taxes. It cannot be determined whether Matthew was a principal customs collector or one of his subordinates. It makes little difference. Very likely Matthew had heard Jesus preach before or at least had heard about His preaching.
Fahling: Long before the eventful day which forever decided his future life he had probably in his heart become a disciple of Jesus. But on account of his social standing, being a despised publican, he did not dare to hope for personal recognition, far less for a call to discipleship. He was mistaken.
Stoeckhardt: No doubt Matthew had heard of Jesus, but had not concerned himself about the great events that had taken place round about him, being steeped in his business of gathering taxes with all of his thinking and planning.
This is Jesus' call.
Stoeckhardt: That one call of Christ had worked this decisive change in Matthew.
The Epitome , Art. XI, Election, Tappert 495.8: This Christ calls all sinners to himself and promises them refreshment. He earnestly desires that all men should come to him and let themselves be helped (Matthew 9:18.104.22.168.29.35.37). To these he offers himself in his Word, and it is his will that they hear the Word and do not stop their ears or despise it. In addition he promises the power and operation of the Holy Spirit and divine assistance for steadfastness and eternal life.
We don't know how much Matthew knew about Jesus prior to this occasion. But we do know that Jesus found and called Matthew, not vice versa. The call of Jesus drew Matthew. Note Matthew's immediate response. He did as Jesus said. He became Jesus' disciple.
Luke 5:29 makes clear what this verse means. We are in Matthew's house, not Jesus' house. We are no longer at the tax-booth. "Reclining" means that Jesus was a guest. For Jesus to eat with a host of publicans and sinners was truly remarkable. "Having gathered." It was not haphazard. Matthew arranged this. Mark adds at this point: "and they were following Him." That must mean that they were attentive to Jesus' Word. They had come to know Jesus just as Matthew had done. They were many in number. According to Luke, Jesus was the primary guest. His disciples came with Him. But Matthew mentions the many publicans and sinners first. This is not a contradiction. Jesus came for just this kind of people, though deeply despised as hopeless people by the Jewish authorities and Jews.
How the Pharisees "saw" or "found out," we do not know. Perhaps they were on a veranda where they could plainly be seen. Perhaps the number caused such a stir that the Pharisees were notified. Surely the Pharisees did not join them. That was against their principles. In any case, they found out.
Likely "asked" means "said repeatedly." Note that they did not speak to Jesus first. They get at Jesus through His disciples. They want to discredit Jesus as a Teacher.
"Why" means "on what grounds, why?" Note only one article with both nouns. They classify publicans with notorious and known sinners. They imply that by eating with them Jesus was lowering Himself to their level or partaking of their sins. The context clearly indicates that quite the opposite was the case.
Note that "eat" is durative present "is customarily eating." Luke 15:2 and 19:7 clearly indicate that Jesus often did this. They are asking: "What kind of a Teacher is this who would lower himself so much?"
Jesus comes to the rescue of the disciples. It would seem that the Pharisees asked the disciples after they left Matthew's house. But then Jesus Himself approached and answered the question put to the disciples. It was a difficult and dangerous situation for the disciples. Note the word order in Jesus' answer. This sentence is an axiom, a proverb understood readily by all people.
The use of "but go" as an imperative by Jesus is interesting. In John 4:50 and Luke 7:50 it means "Be on your way. All is well." In Matthew 10:7 and 28:7 it denotes commands to the regenerate. But at Luke 10:37 Jesus tells the lawyer: "Go and do likewise" implying that he has not yet done so. Likewise, here in Matthew 9:13 Jesus is saying: "Go and do your homework. You have something to learn." "Learn once for all" implies that they do not know.These Pharisees were really guilty of a double sin:
Jesus quotes Hosea 6:6. For an example of what this means see 1 Samuel 15:22. "Mercy I want and not (mere) sacrifice."The divinity of Jesus is implicit in this sentence . It is God Who is speaking. This sentence is used by Jesus again at Matthew 12:7. Jesus is saying to the Pharisees:
Franzmann: He is the Lord their Healer (compare Exodus 15:26; Hosea 11 :3) who does not ignore their sin but deals with it effectually.
Correct. The sacrifices of the Mosaic Law were to be performed on the basis of the mercy and love of God, pointing forward to Christ. The whole book of Hebrews testifies to this. If performed mechanically, apart from God's mercy and love, they became an abomination to God. Compare Isaiah 1:10-15.
Now follows an explanatory "for." Jesus applies the obvious illustration in verse 12 and gives His exegesis of Hosea 6:6. "Come" denotes His coming into the world, His incarnation, John 1:14. God became man for just one purpose: to reveal the grace and truth of God, the saving God.
"To call" is an infinitive of purpose and eliminates all synergism. Matthew did not "make a decision or a commitment." Matthew did not "find" Jesus. The opposite is true. Likewise concerning the other publicans and sinners who attended this reception, put on by Matthew.
Contextually "righteous" must mean "self-righteous." "Righteous" when used of mere men, is always forensic. Either he deludes himself by declaring himself righteous, which is a lie, or, he believes that God declares him righteous for Jesus' sake. A doctor does not heal healthy people. Christ does not call the self-righteous, those who reject Him.
"Sinners" contextually, means "repentant sinners, those who admit that they are sinners." Such Jesus calls to faith. That was what He did for Matthew. That was His purpose in eating with the publicans and sinners. The Pharisees were blind to this. But it would be wrong to say that Jesus did not care about the Pharisees. Surely what He said caused them to think. There is no record of their repenting. But Jesus willed it.
For the word "righteous" TEV has "respectable people" and JB and NEB have "the virtuous." That can be rightly understood, but it is better to keep the expression "the righteous" and to explain it contextually. The translation of LB on this verse is synergistic: "For I have come to urge sinners, not the self-righteous, back to God."
"Repentance" means a lot more than "to urge back." That sounds like they can do it themselves. By the way, note that Jesus purposely and emphatically repeats the word "sinners" in verse 13 from verse 11. They despised sinners. He invited them.
Both Luther, in the Smalcald Articles (Tappert 455,71- 74), and the Formula of Concord (Tappert 582, 69-70) quote Matthew 9:12 with reference to the Lord's Supper.
Luther: If you are heavy-laden and feel your weakness, go joyfully to the sacrament and receive refreshment, comfort and strength. If you wait until you are rid of your burden in order to come to the sacrament purely and worthily, you must stay away from it forever.
The Formula: True and worthy communicants, on the other hand, are those timid, perturbed Christians, weak in faith, who are heartily terrified because of their many and great sins, who consider themselves unworthy of this noble treasure and the benefits of Christ because of their great impurity, and who perceive their weakness in faith, deplore it, and heartily wish that they might serve God with a stronger and more cheerful faith and a purer obedience. This most venerable sacrament was instituted and ordained primarily for communicants like this, as Christ says, Matthew 11:28; Matthew 9:12; 2 Corinthians 12:9.