"Evidence that pluralizing does not necessarily distort the meaning of the text comes from the Bible itself, since biblical writers sometimes translate masculine singular generics with plural constructions. Consider these examples, where the apostle Paul quotes from the Old Testament:
Old Testament Text---------------------------------------------------New Testament Text
Isa. 52:7 :How lovely on the mountains are Rom. 10:15b:...As it is written,'How beautiful
the feet of him who brings good news.-----------------------------are the feet of those who bring good news!'
Ps. 36:1b : There is no fear of God before his eyes. Rom. 3:10, 18 : As it is written... 'There is no fear ___________________________________-----------------------before their eyes.'
Ps. 32:1 : Blessed is he whose transgressions are_______Rom. 4:6-7 : David says the same thing....'Blessed are
forgiven, whose sins are covered. they whose transgressions are forgiven, whose sins are covered.'
_____________________________________________________________________________________________-
In all three cases Paul translated Hebrew singulars with Greek plurals. He clearly recognized that generic plurals in Greek accurately represent the meaning of generic singulars in Hebrew. He changed the form but retained the meaning."
(Taken from How To Choose A Translation For All Its Worth by Fee and Strauss page 105.)
Perhaps Paul was quoting the Septuagint, and not providing a translation from the Hebrew?