Charles Ellicott Commentary Isaiah 12:2

"Behold, God is my salvation; I will trust, and will not be afraid; for Jehovah, [even] Jehovah, is my strength and song; and he is become my salvation." — Isaiah 12:2 (ASV)

Behold, God is my salvation ... —The words also allow for the rendering, Behold the God of my salvation. In either construction, “salvation” is taken, as in the New Testament (John 4:22; 1 Peter 1:9–10), as meaning more than mere deliverance from danger, and including the highest spiritual blessings.

The Lord Jehovah ... —The Hebrew here and in Isaiah 26:4 presents the exceptional combination of the two Divine Names (Yah Yahveh). (See Psalm 68:4.) With this exception, the second clause of the verse is a verbal reproduction of Exodus 15:2.