You can easily see how it fits in, but in thinking about this I believe the quote applies to the season of Advent broadly. You see, the waiting, longing and silence of Advent makes the joy of Christmas all the better.
Malachi, the last book of the Old Testament pre-dates Jesus’ birth by about 400 years, and the years before Malachi were not good years as the people had been taken into captivity. By the time Jesus was born, things were pretty dark and God’s seeming silence made Jesus’ birth all the more wonderful. So just think, in our own dark time where God feels silent if not absent and indifferent, how wonderful it will be when Jesus returns. The song of praise declaring Jesus as holy and worthy—the shout of Hallelujah—will be all the better because of this silence. So let’s enter the silence with the hope of the glorious music to come.