How do we know that Jesus is the arm of the Lord?

In the context of Isaiah 53, 'the arm of the Lord' symbolizes God's divine power and action, particularly in relation to salvation. The New Testament supports this notion by highlighting how Jesus performed miracles and fulfilled prophecies that validate His identity as the Messiah. In John 12, for instance, it is noted that many did not believe in Him, fulfilling Isaiah's question of who has believed our report. The arm of the Lord is, therefore, revealed to those whom God chooses, confirming the sovereign scale of His salvation plan through Christ's sacrificial work.