song. Put by Figure of speech Metonymy (of Adjunct), App-6, for the theme of the song.
salvation. Compare Psalms 118:21.Exodus 15:2.Isaiah 12:2. Put by Figure of speech Metonymy (of Cause), App-6, for Him Who saves. my Saviour.
Related Commentaries of Psalms 118:14
Psalms 118:14
14 The LORD is my strength and song, and is become my salvation.