38 Or “in the spirit.” “Spirit” could refer either to the Holy Spirit or the human spirit, but in either case John was in “a state of spiritual exaltation best described as a trance” (R. H. Mounce, Revelation [], ).
39 Concerning the phrase κυριακῇ ἡμέρᾳ (kuriakē hēmera) κυριακός states: “pert. to belonging to the Lord, the Lord’s … κ. ἡμέρᾳ the Lord’s day (Kephal. I 192, 1; 193, 31 …) i.e. certainly Sunday (so in Mod. Gk.…) Rv 1:10 (WStott, 12, ’65, 70–75).”
40 The conjunction καί (kai) is not introducing a coordinate thought, but one that is logically subordinate to the main verb ἐγενόμην (egenomēn).

In other versions

I was in the Spirit on the Lord’s day, and I heard behind me a loud voice like a trumpet

On the Lord’s Day I was in the Spirit, and I heard behind me a loud voice like a trumpet,

I was in the Spirit on the Lord’s day, and I heard a loud voice behind me like a trumpet

It was the Lord’s Day, and I was worshiping in the Spirit. Suddenly, I heard behind me a loud voice like a trumpet blast.

I was in the Spirit on the Lord’s day, and I heard behind me a great sound like a trumpet

I was in the Spirit on the Lord’s day, and heard behind me a great voice, as of a trumpet,

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