‘And the Lord said to Paul in the night by a vision, “Do not be afraid, but speak and do not hold your peace, for I am with you, and no man shall set on you to harm you, for I have much people in this city.” '
It may be that as the Jewish opposition rose Paul remembered back to previous experiences with fanatical Jews and was considering the possibility of moving on so as to prevent an uprising among the people which might make things difficult for the church, for ‘the Lord' (Jesus Christ) now spoke to Paul in a night vision, urging him to continue the ministry of the word in Corinth, and assuring him of His presence with him, and that there would be no violence against him.
‘I have much people in this city.' This is probably looking ahead prospectively signifying that there were large numbers of people whom He wanted to win for Himself. Alternately it may signify that there had been far more converts than Paul had yet realised, and that the influence of some of them would for the time being prevent any uprisings. Either way he was told not to hold his peace, for God had a work that He wanted to do.