A.T. Robertson Commentary Matthew 8

If thou wilt (εαν θεληις). The leper knew that Jesus had the power to heal him. His doubt was about his willingness. "Men more easily believe in miraculous power than in miraculous love" (Bruce). This is a condition of the third class (undetermined, but with prospect of being determined), a hopeful doubt at any rate. Jesus accepted his challenge by "I will." The command to "tell no one" was to suppress excitement and prevent hostility.

Unto him (αυτω). Dative in spite of the genitive absolute εισελθοντος αυτου as in verse 1, a not infrequent Greek idiom, especially in the koine.

Grievously tormented (δεινως βασανιζομενος). Participle present passive from root βασανος . The boy (παις), slave (δουλος, Luke 7:2), was a bedridden (βεβλητα, perfect passive indicative of βαλλω) paralytic.

I will come and heal him (εγω ελθων θεραπευσω αυτον). Future indicative, not deliberative subjunctive in question (McNeile). The word here for heal (θεραπευσω) means first to serve, give medical attention, then cure, restore to health. The centurion uses the more definite word for healing (ιαθησετα 8:8) as Matthew does in 8:13 (ιαθη). Luke (Luke 9:11), like a physician, says that Jesus healed (ιατο) those in need of treatment (θεραπειας), but the distinction is not always observed. In Ac 28:8 Luke uses ιασατο of the miraculous healings in Malta by Paul while he employs εθεραπευοντο (Acts 28:9) apparently of the practice of Luke the physician (so W. M. Ramsay). Matthew represents the centurion himself as speaking to Jesus while Luke has it that two committees from the centurion brought the messages, apparently a more detailed narrative. What one does through others he does himself as Pilate "scourged Jesus" (had him scourged).

For I also am a man under authority (κα γαρ εγω ανθρωπος υπο εξουσιαν). "Also" is in the text, though the κα here may mean "even," even I in my subordinate position have soldiers under me. As a military man he had learned obedience to his superiors and so expected obedience to his commands, instant obedience (aorist imperatives and aoristic present indicatives). Hence his faith in Christ's power over the illness of the boy even without coming. Jesus had only to speak with a word (8:8), say the word, and it would be done.