‘That it might be fulfilled which was spoken through Isaiah the prophet, saying, “Himself took our infirmities, and bore our diseases”.'
It can hardly be doubted that this quotation from Isaiah is intended to cover at least the whole of the final summary of exorcism and healing, although it is probably also intended to cover the whole passage from Matthew 8:1, and being in the inclusio from Matthew 4:23 to Matthew 9:35, in both of which verses there is specific reference to His healing of both ‘sickness and disease', it is probably intended to cover the whole inclusio. The point being made is that the One Who had come to save His people from their sins (Matthew 1:21) was thus also here to deliver them from the sufferings which resulted from that sin, because He was bearing it all for them. And that included being delivered from the power of the Evil One (Matthew 8:16). And He was able to do it because He would bear their necessary sufferings on Himself. As the original context makes clear (and see also Matthew 20:28) He was here as our representative and substitute to bear in Himself what the world deserved because of sin (Isaiah 53:3-5). Among other things He would take on Himself the groaning of the world (Romans 8:18-25). Thus these acts of healing were a part of His larger work as the suffering Servant Who would lay down His life as a guilt offering on behalf of many, with all its positive results (Isaiah 53:10), the Servant Who was also the coming King (Isaiah 52:13; Isaiah 42:1; Isaiah 42:4). And this offering would result in healing and forgiveness (Matthew 9:12-13). We must again draw attention to the fact that we are in the part of Matthew where the quotations from Isaiah specifically predominate, referring to both King and Servant. Jesus is revealed as having come here as the suffering Servant, and as in fulfilment of all the Isaianic promises (Matthew 3:3; Matthew 4:16; Matthew 8:17; Matthew 12:17; Matthew 13:14-15).
The word for ‘infirmities' is used only here in Matthew. Luke, however, uses it regularly for diseases. The dual idea, but with a different term for infirmities, is again found in Matthew 4:23; Matthew 9:35; Matthew 10:1. If we consider the probability that Matthew uses ‘infirmities' (astheneias) here simply because it was in the text from which he took the saying, while himself preferring ‘sicknesses' (malakian) as in Matthew 4:23; Matthew 9:35; Matthew 10:1, then we might see Matthew 8:17 as central to the inclusio from Matthew 4:23 to Matthew 9:35 (both of which mention the dual ‘sickness and disease'), demonstrating that what lies between is to be connected with Matthew 8:17. In that case Matthew 10:1, where ‘sicknesses and diseases' are again mentioned, can then be seen as also carrying the implication forward into the future work of His disciples. They too are in a sense God's Servant (compare Acts 13:47).