“As the deer pants for streams of water, so my soul pants for you, my God.”
Many times Psalms will say, as with Psalm 42, that it is for the director of music. So why don’t we sing it? I mean, we need to hide His word in our hearts (Read Psalm 119:11 –http://bit.ly/3aUiefp).
So when we sing songs based on or straight from scripture, we’re memorizing it and hiding it in our hearts. When our soul is longing for God (which is all the time) we can sing and praise Him with His Word!