As I urged you when I went into Macedonia, stay there in Ephesus so that you may command certain men not to teach false doctrines any longer (NIV)
Start with the first phrase, "As I urged you when I went into Macedonia". Macedonia was a Roman province established in 146 B.C. Its economy focused on agriculture and livestock although some metals and other products such as timber and hemp were also exported. Important cities such as Thessalonica and Berea were situated inside of Macedonia. There's not much we can tell from this phrase other than that Paul wanted to visit Macedonia.
Moving on, we come to the clause "stay there in Ephesus so that you may command certain men not to teach false doctrines any longer". The main part of this verse it the section dealing with false doctrine. The greed word for "false" in this verse means "other". Paul was making simple for Timothy and for us; instead of leaving it up to us to determine whether a doctrine was true or not he gave us a simple test. If the doctrine in question didn't agree with what Paul had already taught, if it fit in the "other" category, then it was not to be taught at all. This also illustrates Paul's authority in teaching. Anything that opposed what he taught (given by God) was false.