This was to fulfill1 what was spoken through the prophet Isaiah:
References for Matthew 12:17
"Here is my servant whom I have chosen, the one I love, in whom I delight;2 I will put my Spirit on him,3 and he will proclaim justice to the nations.
References for Matthew 12:18
He will not quarrel or cry out; no one will hear his voice in the streets.
A bruised reed he will not break, and a smoldering wick he will not snuff out, till he leads justice to victory.