‘And he says, “Write. For these words are faithful and true”. And he said to me, “They have come about. I am the Alpha and the Omega, the beginning and the end, and I will give freely to him who is thirsty of the water of life”.'
Elsewhere it is Christ, the Word of God, Who is faithful and true (Revelation 19:11, compare Revelation 3:14). It is He Who is the faithful witness (Revelation 3:14, compare Revelation 1:5). But now God's words spoken here are also faithful and true. There is no doubt of their fulfilment for they are the promises of One Who can be fully relied on.
‘They have come about' - in the new Jerusalem all that He has promised has happened, and can be seen as already fulfilled. (This phrase is written as ‘It is done' in an equal number of authorities - compare Revelation 16:17, but the final significance is the same).
For ‘I am the Alpha and the Omega (see on Revelation 1:8 and compare Revelation 1:17), the beginning and the end' (see also Revelation 22:13). All things came from Him, He is the source of all things, and all things lead to Him so that He is all in all (1 Corinthians 15:28). Thus He sums up in Himself the whole of existence. And that in itself is the guarantee of the fulfilment of His future purposes and promises.
‘I will give freely to him who is thirsty of the water of life.' This was the cry of the water-seller on God's behalf in Isaiah 55:1, water, wine and milk without money and without price. Compare also John 7:37, ‘if any man thirst let him come to me and drink'. Water was the life-giving commodity that all men craved. Without it they could not survive for it was the very basis of life. Now it is freely available as the water of life (see Revelation 22:1; Revelation 22:17). Here is promised fullness of life.