Matthew Henry Presbyterian @wholebiblehenry

We have now come to that glorious vision which the apostle had of the Lord Jesus Christ, when he came to deliver this revelation to him, where observe, I. The account given of the person who was favoured with this vision. He describes himself, 1. By his present state and condition. He was the brother and companion of these churches in tribulation, and in the kingdom and patience of Christ.

Commenting on Revelation 1:9-20

John Gill Reformed Baptist @doctorgill

I was in the Spirit on the Lord's day,.... Not on the Jewish sabbath, which was now abolished, nor was that ever called the Lord's day, and had John meant that, he would have said on the sabbath day; much less the Jewish passover, but the first day of the week is designed; so the Ethiopic version renders it "on the first day"; and is...

Albert Barnes Presbyterian @notesbybarnes

Verse 10. I was in the Spirit. This cannot refer to his own spirit--for such an expression would be unintelligible. The language then must refer to some unusual state, or to some influence that had been brought to bear upon him from without, that was appropriate to such a day.