The night is coming — Christ is the light. When the light is withdrawn night comes, when no man can work — No man can do any thing toward working out his salvation after this life is ended. Yet Christ can work always. But he was not to work upon earth, only during the day, or season which was appointed for him.
Related Commentaries of John 9:4
John 9:4
4 I must work the works of him that sent me, while it is day: the night cometh, when no man can work.