Kim Paffenroth, «Jesus as Anointed and Healing Son of David in the Gospel of Matthew», Vol. 80 (1999) 547-554
Matthew handles his material in order to relate Jesus anointing, healing, and his title "Son of David". Matthew does this in order to present Jesus as the uniquely anointed "Christ", the Son of David who has come to heal, and who is in that respect (and others), greater than his father David.
In his redaction of Markan material, Matthew has consistently shown that he is more interested in depicting Jesus as a healer than is Mark: he has made some exorcisms into more generalized healings, he has depicted Jesus as healing rather than teaching several times, and he has summarized Jesus ministry as one of "teaching and healing" rather than "teaching and casting out demons".
There is one final, but all-important observation to be made about Jesus healing in Matthew. As observed above, Matthew omits Mark 6,13, thereby making Jesus the only person anointed in Matthews Gospel. Just as importantly, however, this omission removes any reference to anyone other than Jesus healing in Matthews Gospel24. Both Mark and Luke include some mention of the disciples healing mission being (at least partially) successful: "[the disciples] anointed with oil many that were sick and healed them" (Mark 6,13), "they departed and went through the villages... healing everywhere" (Luke 9,6). In Matthew, Jesus is not only uniquely anointed, he is also uniquely capable of healing, or indeed of performing any powerful deed, since Matthew has also omitted the story of the strange (but successful) exorcist (Mark 9,38-41 // Luke 9,49-50). Through seemingly minor omissions, Matthew has made Jesus status and power unique in several important ways.
3. Son of David
As for the title Son of David, its prominence in Matthew has often been noted, and the exact meaning he attaches to it has often been explored25. Both placement and frequency point to the titles importance for Matthew. He begins his Gospel with, "Jesus Christ, Son of David" (Matt 1,1), and the title occurs nine times in Matthew26, versus only three in Mark27. The most obvious implications of the title are those associated with David (and therefore his son) as king28. David was anointed king (1 Sam 16,1-13) and now Matthew presents Jesus as the "Christ", the anointed. Promises were made to David regarding his progeny (2 Sam 7,12-16), promises that Matthew sees fulfilled in Davids (adopted) son Jesus29.