2 Corinthians 1:20

For all the promises of God in Him are yea. All the promises of God in the Old Testament relating to the Messiah were constant and true, and have been fulfilled in Him.

1 The yea yea here, and in S. Matthew 5:47, have a threefold signification: (1.) constant asseveration, as opposed to inconstancy and deceit; (2.) truth or reality, as opposed to falsity or unreality; (3.) simple affirmation, as opposed to an oath. Cf. S. James 5:12.

And in Him Amen. "And therefore we say, Amen" is the Latin rendering; that is, we affirm that those promises were true. So Chrysostom and Ambrose. For further notes on "Amen," see 1 Cor. xiv. 16.

Add to this that Amen is usually an adverb denoting truly, firmly, faithfully, and thence came to be the name of the abstract qualities of truth, firmness, and faithfulness. Cf. Isaiah 65:16; Jeremiah 11:5; Isaiah 25:1; Revelation 3:14; Revelation 7:12. The meaning, therefore, here is: Through Him, Christ, the Amen, i.e., truth, faithfulness, and constancy, we give glory to God, saying: All that God promised concerning Christ is Amen, i.e., most true, and has been most truly fulfilled by God.