…Grace to you and peace, from Him who is (ὁ ὢν) and who was and who is to come… (Rev 1:4-5 NAS)
The word translated ‘him who is’ (ὁ ὢν) is not proper Greek, but is the exact word used in the Septuagint to translate the Divine Name revealed in Exodus 3:14. (1) The Apostle John is clearly making a connection between the two.
God said to Moses, “I AM WHO I AM.” (Grk. – ἐγώ εἰμι ὁ ὤν) And he said, “Say this to the people of Israel, ‘I AM (ὁ ὢν) has sent me to you.'” (Exo 3:14 ESV)
There has been some debate about what is the best translation of the phrase I AM WHO I AM. The form of the verb is in the imperfect (Heb. – ‘ahieh asher ahieh’), and so some think it is better to translate the phrase ‘I will be what I will be’ or “I will cause to be what I will cause to be’ . However, the traditional translation – ‘I AM WHO I AM’ – receives strong support from the Septuagint where both the participle and the verb used in the translation of ‘I am that I am‘ are in the present tense. This translation is further bolstered by the apostle John who, as we have seen, interprets the clause ‘I AM WHO I AM’ to be the totality of existence.
‘from him who is and who was and who is to come…’
‘I am that I am…’
(1) The NET Bible notes point out that the antecedent of the preposition ‘apo’ is usually in the genitive and never the nominative. But here in Rev. 1:4 and again in Rev. 1:8, the antecedent of the preposition ‘apo’ is in the nominative form (ὁ ὢν). If one looks at this from a purely grammatical perspective, then the author seems to have made a grammatical mistake but when one looks at the context, it is clear that John intends to connect his use of the word with the Divine Name revealed in Exo. 3:14.