In his sermon on Luke 2:22-32, Martin Luther made the profound observation that by faith Simeon saw in Mary’s poor, beggar baby the King of Kings, and Savior of the world. He wrote:
Simeon has a very penetrating eye. In this child this is no kingly mien or royal garb to see, merely the form of a poor beggar. The mother is poor, with hardly five pennies in her purse to redeem her child in keeping with the law. The child is wrapped in very poor swaddling clothes. Nevertheless, Simeon comes right up, without anyone’s testimonial, and publicly attests: This child is the Savior of the world and a Light to all the Gentiles. This is a remarkable sermon and wonderful witness on behalf of this child, as Simeon looks upon this little infant wrapped in shabby rags. By reasoned judgment he would have to say, “This is no king, but a beggar child.” But he does not allow his reason to judge by what his eyes behold, but denominates this child as a king, greater than all the kings in the world. For he calls Him a Savior, prepared by God for all nations, and a Light to lighten the Gentiles all over the world. Indeed for Simeon, this was to open one’s eyes wide and look far beyond oneself. His eyes behold the whole world, from one end of the earth to the other. Wherever, in the whole world, he says, there are peoples and Gentiles, there this child is a Savior and a Light. Thus he comprehends everything that the Holy Scriptures state, and associates it with the child now lying in his arms.
You can read the whole sermon here.