Rev 2:8-11

THE SPIRIT TO SMYRNA
8 “To the angel of the assembly in Smyrna write: “The first and the last, who was dead, and has come to life says these things: 
Rev 2:8
The first and the last, who was dead and has come to life – the Spirit of Christ reinforces His identity as the man Christ Jesus. Christ seems to call Himself “the First and the Last.” But in fact, Christ was the “Word” in the Old Testament, who spoke “as one” with the invisible God, and now continues to speak for God, after the Lord’s Day. This was noted by Irenaeus as mentioned at Rev 2:7.
9 “I know your oppression, and your poverty (but you are rich), and the blasphemy of those who say they are Jews, and they are not, but are a synagogue of Satan.
Rev 2:9
(but you are rich) – the riches of the kingdom of heaven surpass anything in this world.

the blasphemy of those who say they are Jews and are not, but are a synagogue of Satan – why did Jesus use such strong language? This kind of strong language was also used by Paul to the Galatians: “if anyone brings you another gospel let him be eternally condemned” (Gal 1:8-9). Paul admonished the Gentiles not to observe the Jewish religious days: “you observe days and months….” (Gal 4:10). This was “another gospel.” The Gospel that Christ died for was the worship of God in the Spirit (Gal 3:2). We should not worship God, as Paul said: “according to the basic principles of this world” (Gal 4:9; Col 2:8). Yet, the Gentiles continued on their path of observing the Jewish days, including the Passover, the Preparation and the Day of Pentecost. To these, they added more days, leaving the worship of God in the holy spirit for a different gospel.
10 Don’t be afraid of the things which you are about to suffer. Behold, the devil is about to throw some of you into prison, that you may be tested; and you will have oppression for ten days. Be faithful to death, and I will give you the crown of life. 11 He who has an ear, let him hear what the Spirit says to the assemblies. He who overcomes won’t be hurt by the second death.
Rev 2:10
you will have tribulation for 10 days – there are two explanations for this. The first is that there were ten persecutions from Nero to Diocletian; ten “days” as ten periods of persecution. The second explanation is that the Great Persecution lasted ten years. Throughout Daniel and Revelation, days are actually years, and so the “ten days” here can mean “ten years.”

I will give you the crown of life – the Greek word for crown describes an Olympic garland of victory. A diadem, in contrast, is a thin band, worn in battle.

Rev 2:11
not be hurt by the second death – on the judgment day.