Revelation 1:10

I was in the Spirit on the Lord's day,— That is, the day which we in general call Sunday; denominated the Lord's day, in memory of his resurrection from the dead. That the primitive Christians set this day apart for religious worship, appears both from St. Paul's Epistles, and from Justin Martyr's Apology, Ignatius, Tertullian, &c. It should be observed, that this Revelation was given on the Lord's day, when the apostle's heart and affections, as we may reasonably suppose, were peculiarly sublimed by the meditations and devotions of the day, and rendered more capable of receiving divine inspiration. The heavenly visions were vouchsafed to St. John, as they were before to Daniel, (ch. Revelation 9:20.) after supplication and prayer; and there being two kinds of prophetic revelation, in a vision, and a dream, the Jews accounted a vision superior to a dream, as representing things more perfectly, and to the life; so that this book is represented as the highest degree of prophetic revelation.