Charles Ellicott Commentary Matthew 9:29

"Then touched he their eyes, saying, According to your faith be it done unto you." — Matthew 9:29 (ASV)

Then He touched their eyes. This is the first recorded instance of the method our Lord seems to have consistently adopted in the case of the blind and, in part, also for the deaf.

Others might have their faith strengthened by the look of sympathy and conscious power they saw in the face of the Healer. They were shut out from that influence, and therefore, for them, this absence was supplied by actions they would naturally connect with the purpose of healing them (Compare the later instances in Matthew 20:34 and John 9:6).