Strong's Concordance
Enter a Strong's number (G for Greek, H for Hebrew).
You can find these numbers in interlinear Bibles or Strong's concordances.
ESV
Whoever receives his testimony sets his seal to this, that God is true.
KJV
He that hath received his testimony hath set to his seal that God is true.
NKJV
He that hath received his testimony hath set to his seal that God is true.
enLXX
Not available for this version yet.