These words occur three times in the Bible: here, in Isaiah xii.2, and in Psalm cxviii.14.
I. The lessons from the various instances of their occurrence. The first and second teach that the Mosaic deliverance is a picture- prophecy of the redemption in Christ. The third (Psalm cxviii.14), long after, and the utterance of some private person, teaches that each age and each soul has the same mighty Hand working for it. 'As we have heard, so have we seen.'
II. The lessons from the words themselves.
(a) True faith appropriates God's universal mercy as a personal possession. 'My Lord and my God!' 'He loved me, and gave Himself for me.'
(b) Each single act of mercy should reveal God more clearly as 'My strength.' The 'and' in the second clause is substantially equivalent to 'for.' It assigns the reason for the assurance expressed in the first. Because of the experienced deliverance and God's manifestation of Himself in it as the author of 'salvation,' my faith wins happy increase of confidence that He 'is the strength of my heart.' Blessed they who bring that treasure out of all the sorrows of life!
(c) The end of His deliverances is 'praise.' 'He is my song.' This is true for earth and for heaven. The 'Song of Moses and the Lamb.'