Paul was undoubtedly wondering how he would ever get out of the mess in which he found himself. At this critical moment, during the night of the next day (Gr. te epiouse nykti), the Lord appeared to him again (cf. 9:4-6; 16:9; 18:9-10; 22:17-21; 27:23-24; Gen. 15:1). The Lord's appearances to Paul all occurred at great crises in his life. He assured the apostle that he would bear witness in Rome as he had already done in Jerusalem (1:8). This revelation is essential to Luke's purpose in writing Acts, and it certainly must have given Paul confidence as the events that followed unfolded.
"When Jesus' witnesses were previously imprisoned, prison doors were wondrously opened for them (5:17-21; 12:1-11; 16:23-26). That is no longer the case. The Lord's reassurance must take the place of miraculously opening doors. The divine power that rescues from prison has become a powerful presence that enables the witness to endure an imprisonment that lasts for years."882
"This assurance meant much to Paul during the delays and anxieties of the next two years, and goes far to account for the calm and dignified bearing which seemed to mark him out as a master of events rather than their victim."883
