Religious song from son in tree (5)
I believe the answer is:
psalm
'religious song' is the definition.
(I've seen this before)
'son in tree' is the wordplay.
'son' becomes 's'.
'in' means one lot of letters goes inside another.
'tree' becomes 'palm' (palm tree is a kind of tree**).
's' going into 'palm' is 'PSALM'.
'from' acts as a link.
(Other definitions for psalm that I've seen before include "Sacred song from Old Testament" , "Devotional hymn or song" , "Religious chant" , "Song - hymn - prayer" , "Old Testament lyrical poem or prayer" .)