Albert Barnes Commentary John 9:4

"We must work the works of him that sent me, while it is day: the night cometh, when no man can work." — John 9:4 (ASV)

The works of him, etc. The works of beneficence and mercy which God has commissioned me to do, and which are expressive of His goodness and power. This was on the Sabbath day (John 9:14); and though Jesus had endangered His life (John 5:1–16) by working a similar miracle on the Sabbath, He knew that it was the will of God that He should do good, and that God would take care of His life.

While it is day. The day is the proper time for work — night is not. This is the general, the universal sentiment. While the day lasts, it is proper to labor.

The term day here refers to the life of Jesus and to the opportunity thus afforded for working miracles. His life was drawing to a close. It was probably only about six months after this when He was put to death. The meaning is, My life is near its close. While it continues, I must employ it in doing the works which God has appointed.

The night cometh. Night here represents death. It was drawing near, and He must therefore do what He had to do soon. It is not improbable, also, that this took place near the close of the Sabbath, as the sun was declining, and the shades of evening were about to appear. This supposition will give increased beauty to the language that follows.

No man can work. It is literally true that day is the appropriate time for toil, and that the night of death is a time when nothing can be done. Ecclesiastes 9:10: There is no work, nor device, nor knowledge, nor wisdom in the grave. From this we may learn:

1. That it is our duty to employ all our time in doing the will of God.
2. That we should seek opportunities for doing good, and allow no opportunity to pass without making good use of it. We pass through the world only once, and we cannot return to correct errors and reclaim neglected opportunities to do our duty.
3. We should be especially diligent in doing our Lord's work because the night of death is coming. This applies to the aged, for they must soon die; and to the young, for they may soon be called away from this world to eternity.