As the complete God, signified by the arm of Jehovah, the power of God (v. 1b; 1 Cor. 1:24), Christ became a perfect man, signified by a man of sorrows (v. 3a; John 1:1, 14; 1 Tim. 2:5b). The Old Testament term is the arm of Jehovah, whereas the New Testament term is the power of God. First Corinthians 1:22-24 says, "For indeed Jews require signs and Greeks seek wisdom, but we preach Christ crucified, to Jews a stumbling block, and to Greeks foolishness, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God." In these verses Christ crucified corresponds to the man of sorrows in Isaiah 53:3, and the power of God equals the arm of Jehovah in Isaiah 53:1. Thus, in these two portions of the Word, incarnation is clearly mentioned.
As a perfect man, Christ lived a lowly and sorrowful human life. His birth was lowly, and His family also was in a lowly state. His living was also full of sorrow.
First, He grew up like a tender plant (like a small, delicate person) before Jehovah (Isa. 53:2a). The plant here actually refers to a sprout, which is very tender, small, and delicate. Christ did not grow up like a large tree, but like a small, delicate sprout. Because He was such, no one would pay any attention to Him. He also grew up like a root out of dry ground, meaning that He was born of a poor family. His mother, Mary, and her husband, Joseph, lived in a despised city called Nazareth, in a despised region, Galilee. It is true that they were descendants of David, but David reigned approximately one thousand years before Jesus was born. When Mary and Joseph came into being, the royal family had become insignificant. In Isaiah 11:1 the royal family of Jesse was likened to the stump of a tree. From that stump a sprout, Christ, came out. Hence, His birth was very lowly.