Lit., I have given. For a similar phrase see Luk 12:51.
An open door (θύραν ἀνεῳγμένην)
Rev., more literally, a door opened. This is variously explained. Some refer it to the entrance into the joy of the Lord; others to the initiation into the meaning of scripture; others again to the opportunity for the mission-work of the Church. In this last sense the phrase is often used by Paul. See 1Co 16:9; 2Co 2:12; Col 4:3. Compare Act 14:27. I have given is appropriate, since all opportunities of service are gifts of God. See on Rev 2:7.
For thou hast (ὅτι ἔχεις)
Some texts make behold-shut parenthetical, and render ὅτι that, defining thy works, etc. So Rev.
A little strength (μικρὰν δύναμιν)
This would mean, thou hast some power, though small. Many, however, omit the indefinite article in translating, and render thou hast little strength; i.e., thou art poor in numbers and worldly resources. So Alford, Trench, and Düsterdieck.
And (καὶ)
John's single copula instead of a particle of logical connection. See on Joh 1:10; see on Joh 6:46; see on 1Jo 1:5; see on Joh 8:20.
Hast kept my word (ἐτήρησάς μου τὸν λόγον)
Rev., rendering the aorist more strictly, didst keep. For the phrase, see Joh 17:6, Joh 17:8.