The first Exodus for God’s people was from Egypt. The second Exodus is for the exiles in Isaiah. The greatest Exodus would be for all people with Jesus.
Grace is God’s attitude towards sinners; not holding their sins against them but relenting from the Law’s just judgement and giving the undeserved Gospel instead.
The prophet is clear that this coming King would be different from the common experience of kings, both in Israel and among all the kings of the earth.
The promise between God and Abraham reflects God’s relationship with all of His people, which includes the Church, and through the Church to each one of us.