A.T. Robertson Commentary 2 Thessalonians 2:5

"Remember ye not, that, when I was yet with you, I told you these things?" — 2 Thessalonians 2:5 (ASV)

When I was yet with you (ετ ων προς υμας). The present participle takes the time of the verb ελεγον (imperfect active),

I used to tell you these things . So Paul recalls their memory of his words and leaves us without the clue to his idea. We know that one of the charges against him was that Jesus was another king, a rival to Caesar (Acts 17:7). That leads one to wonder how far Paul went when there in contrasting the kingdom of the world of which Rome was ruler and the kingdom of God of which Christ is king. Frame notes Paul's abrupt question here "with an unfinished sentence behind him" (verses 3f.), even "with a trace of impatience."