“Whoever invokes a blessing in the land will do so by the God of truth; he who takes an oath in the land will swear by the God of truth” (Isa 65:16).
“Abraham was told that all nations would bless themselves in his Seed (Psa 72:17). With reference to these superlative truths, Paul declared with warm emphasis that ‘For no matter how many promises God has made, they are “Yes” in Christ. And so through him the “Amen” is spoken by us to the glory of God’ (2Co 1:20). To this the Lord Jesus adds his own assurance:
‘These are the words of the Amen, the faithful and true witness, the ruler of God’s creation’ (Rev 3:14).
‘Behold, I am alive for evermore, the Amen; and have the keys of death and of the grave’ (as promised to Abraham: Gen 22:17a)”
(Harry Whittaker, “Isaiah” 542).