A.T. Robertson Commentary 1 Timothy 4:5

"for it is sanctified through the word of God and prayer." — 1 Timothy 4:5 (ASV)

It is sanctified (αγιαζετα). Present passive indicative of αγιαζω, here "rendered holy" rather than "declared holy." Cf. verse 4.

Through the word of God and prayers (δια λογου θεου κα εντευξεως). See 2:1 for εντευξις. Paul seems to refer to Genesis 1. It is almost a hendiadys "by the use of Scripture in prayer."