They spent ten days with one accord thinking and praying about all that had been done within the time that Jesus Christ had been in front of them. Both what He said and did, along with their responses to those things.
Brethren, as I said, all metaphors break down, but the work of Jesus Christ never does, and the missing piece for the constancy of looking to Christ as the Author and Finisher of our faith is baptism of the Spirit, with the Father and Son dwelling within those Christ has determined to serve His Body! It ensures those gifted members of His Body will serve with eyes focused on Him, constantly and consistently.
A dozen or so versions read that the cloud, Hid Him from their sight, which is actually more accurate. This depiction fits well into the idea of clouds hiding and moving. Drop down to verse 11, where two angels speak to the spellbound disciples:
Same is the operative word here. The two angels provide two witnesses, as it were, that Christ will come again in the same way He ascended. And, He ascended in a cloud, so He will return in a cloud. This passage gives insight into the Day of the Lord, when Christ returns.
Does it also fit other prophecies about the Day of the Lord? Turn to Matthew 24, the Olivet Prophecy:
Forty days had passed and the resurrected Christ had been right there before them proclaiming the Kingdom of God and all that He fulfilled in the law and the prophets! But they still did not get it. Their hearts may have burned when He was in front of them, but they still were not fully grasping things.
They merely saw Him as the leader of a physical revolution that fell far short of what the Father and Son actually had in mind—the real change God wanted was to turn the whole world upside down (Acts 17:6).