During the Olympic games of 324, Alexander announced that all exiles in all Greek towns were allowed to return. It is questionable whether he was entitled to do this, even though he was leader of the Corinthian league. The result was that in nearly all towns civil discord flared up - something that may have been intended, to give Alexander an excuse to intervene and tighten his grip on the Greek towns. The Greek author Diodorus of Sicily describes the decree in chapter 18.8.2-7 of his Library of world history. The translation below was made by M.M. Austin.
Alexander's Decree on the Exiles
[18.8.2] Not long before his death Alexander decided to bring back all the exiles in the Greek cities, partly to increase his own glory and partly to have in each city many personal supporters to counteract the risk of revolution and revolt among the Greeks.
[18.8.3] Consequently, as the celebration of the Olympic Games was imminent,note[Celebrated in July or August 324.] he dispatched Nicanor of Stagiranote[Maybe a relative of the philosopher Aristotle of Stagira.] to Greece with a letter about the exiles' recall; his instructions were to have it read out by the victorious heraldnote[A contest of heralds opened the games.] to the assembled crowds.
[18.8.4] Nicanor carried out the order, and the herald took and read out the following letter.
King Alexander to the exiles from the Greek cities. We were not the cause of your exile, but we shall be responsible for bringing about your return to your native cities, except for those of you who are under a curse.note[People who were exiled as a punishment for a religious crime were not recalled. Only political exiles were allowed to return.] We have written to Antipaternote[Alexander's deputy in Europe.] about this matter so that he may apply compulsion to those cities which refuse to reinstate their exiles.
[18.8.5] This proclamation was greeted with loud approval by the crowd; for those at the festival joyfully welcomed the king's favor and repaid his generosity with shouts of praise. All the exiles had gathered together at the festival, being more than 20,000 in number.
[18.8.6] The majority of Greeks welcomed the return of the exiles as a good thing.