But if the cloud were not taken up, then they journeyed not till the day that it was taken up.

Matthew Henry's Concise Commentary

40:34-38 The cloud covered the tabernacle even in the clearest day; it was not a cloud which the sun scatters. This cloud was a token of God's presence to be seen day and night, by all Israel, that they might never again question, Is the Lord among us, or is he not? It guided the camp of Israel through the wilderness. While the cloud rested on the tabernacle, they rested; when it removed, they followed it. The glory of the Lord filled the tabernacle. In light and fire the Shechinah made itself visible: God is Light; our God is a consuming Fire. Yet so dazzling was the light, and so dreadful the fire, that Moses was not able to enter into the tent of the congregation, till the splendour was abated. But what Moses could not do, our Lord Jesus has done, whom God caused to draw near; and who has invited us to come boldly, even to the mercy-seat. Being taught by the Holy Spirit to follow the example of Christ, as well as to depend upon him, to attend his ordinances, and obey his precepts, we shall be kept from losing our way, and be led in the midst of the paths of judgment, till we come to heaven, the habitation of his holiness. BLESSED BE GOD FOR JESUS CHRIST!