Moses went into the cloud when he went up the mountain, and Moses was on the mountain forty days and forty nights.—Exod 24:18 NET
The life of fellowship with God cannot be built up in a day. It begins with the habitual reference of all to Him, hour by hour, as Moses did in Egypt. But it moves on to more and longer periods of communion; and it finds its consummation and bliss in days and nights of intercession and waiting and holy intercourse. — F. B. Meyer.