Acts 20:31

Wherefore watch ye (dio grhgoreite). Paul has concluded his defence of himself and his warning. Now he exhorts on the basis of it (dio) because of which thing. The very command of Jesus concerning the perils before his return as in Mark 13:35 (grhgoreite), the very form (late present imperative from the second perfect egrhgora of egeirw, to arouse). Stay awake. I ceased not to admonish (ouk epausamhn nouqetwn). Participle describes Paul, I did not cease admonishing, night and day (nukta kai hmeran, accusative of extent of time, for three years trietian, accusative of extent of time also). Nouqetwn is from nouqetew, to put sense into one. So Paul kept it up with tears (verse Mark 19 ) if so be he could save the Ephesians from the impending perils. Forewarned is to be forearmed. Paul did his duty by them.