Charles H. Spurgeon on Psalms 118:21

Having entered, the champion exclaims, I will praise thee, not "I will praise the Lord, "for now he vividly realizes the divine presence, and addresses himself directly to Jehovah, whom his faith sensibly discerns. How well it is in all our songs of praise to let the heart have direct and distinct communion with God himself! The Psalmist's song was personal praise too: —"I will praise thee"; resolute praise, for he firmly resolved to offer it; spontaneous praise, for he voluntarily and cheerfully rendered it, and continuous praise, for he did not intend soon to have done with it. It was a life long vow to which there would never come a close, "I will praise thee." For thou hast heard me, and art become my salvation. He praises God by mentioning his favours, weaving his song out of the divine goodness which he had experienced. In these words he gives the reason for his praise, —his answered prayer, and the deliverance which he had received in consequence. How fondly he dwells upon the personal interposition of God! "Thou hast heard me." How heartily he ascribes the whole of his victory over his enemies to God; nay, he sees God himself to be the whole of it: "Thou art become my salvation." It is well to go directly to God himself, and not to stay even in his mercy, or in the acts of his grace. Answered prayers bring God very near to us; realised salvation enables us to realise the immediate presence of God. Considering the extreme distress through which the worshipper had passed, it is not at all wonderful that he should feel his heart full of gratitude at the great salvation which God had wrought for him, and should at his first entrance into the temple lift up his voice in thankful praise for personal favours so great, so needful, so perfect. This passage (Ps 118:22-27) will appear to be a mixture of the expressions of the people and of the hero himself.