I John (Εγω Ιωανης). So Revelation 22,8Daniel 8,1Daniel 10,2

Partaker with you (συνκοινωνος). See already 1. Corinthians 9:23Römer 11,17Matthäus 13,21Matthäus 3,2Lukas 8,15Jakobus 5,7Offenbarung 14,13Offenbarung 3,202 Thessalonians 3:5

Was (εγενομην). Rather, "I came to be," second aorist middle indicative of γινομα.

In the isle that is called Patmos (εν τη νησω τη καλουμενη Πατμω). Patmos is a rocky sparsely settled island some ten miles long and half that wide, one of the Sporades group in the Aegean Sea, south of Miletus. The present condition of the island is well described by W. E. Geil in The Isle That Is Called Patmos (1905). Here John saw the visions described in the book, apparently written while still a prisoner there in exile.

For the word of God and the testimony of Jesus (δια τον λογον του θεου κα την μαρτυριαν Ιησου). The reason for (δια and the accusative) John's presence in Patmos, naturally as a result of persecution already alluded to, not for the purpose of preaching there or of receiving the visions. See verse Revelation 1:2 for the phrase.