“The arm of the Lord” in Isaiah 53:1 refers to God's strength and mighty power. The "dry ground" is Israel. Spiritually, Israel was not a paradise but was a dried-up desert. The "tender shoot" of Jesus growing up in the "dry ground" that was Israel points to unusual or unlikely circumstances. Jesus did not come on as a king or a strong military leader. He came as a baby, grew up in a Jewish family and looked like all other Jewish men. As Isaiah 53:2 says, “There was nothing beautiful or majestic about this appearance.” All of this - a root sprouting in the desert and an ordinary man saving humanity - teaches us to remember that God does things in unexpected ways. God didn’t use the most powerful, best looking, most popular or majestic man in perfect conditions in order to save the world. He used an ordinary man in difficult circumstances.
In light of Exodus 6:6, Deuteronomy 4:34, and Psalm 98:1-3, along with representing God’s strength, “the arm of the Lord” also represents his mercy and his salvation available to all people. The Lord’s powerful arm is outstretched as a symbol to all that He reaches out to us and extends his offer of mercy. To extend the metaphor even further, Jesus is the arm of the Lord and the strength of the Lord in the world. He represents God, performing miracles and healing the sick in order to draw people to God and extend salvation and eternal life to them.