This piece is based on William Croft's (1678-1727) magnificent tune, "Hanover" dating from 1720.
It is a brilliant "toccata" that is played entirely on the Full Swell, with the Pedal stating the unadorned tune on Foundation 32', 16', and 8', with Reeds at 16' & 8'.
This is the 5th piece in the collection of "12 Short Preludes on Old English Psalm Tunes", and is the most well-known of the group. It really is a fine work, as it shows elements of canon, and is sort of a "combination" of German and English elements - as was most English music of the period.
Best quotes the text used as "My soul, praise the Lord", but I think ALL of us will know this one as "O worship, the King, all glorious above".
At any rate, I'm sure the "sentiment" of the text is the "same" in both cases... ;-)