Albert Barnes Commentary Acts 1:12

"Then returned they unto Jerusalem from the mount called Olivet, which is nigh unto Jerusalem, a Sabbath day`s journey off." — Acts 1:12 (ASV)

Then returned they unto Jerusalem. In Luke 24:52, we are told that they worshipped Jesus before they returned. And it is probable that the act of worship to which he refers was that which is mentioned in this chapter—their gazing intently on their departing Lord.

From the mount called Olivet. From the Mount of Olives. See Barnes on Matthew 21:1.

The part of the mountain from which he ascended was the eastern slope, where the little village of Bethany stood (Luke 24:50).

A sabbath day's journey. This was as far as a Jew might lawfully travel on the Sabbath. It was two thousand paces or cubits, or seven furlongs and a half—not quite one mile. See Barnes on Matthew 24:20.

The distance of a lawful journey on the Sabbath was not determined by the laws of Moses, but Jewish teachers had fixed it at two thousand paces. This measure was determined because it was a tradition that in the camp of the Israelites, when coming from Egypt, no part of the camp was more than two thousand paces from the tabernacle. Therefore, over this space, they were permitted to travel for worship.

Perhaps this was also supported by the fact that this was the extent of the suburbs of the Levitical cities (Numbers 35:5). Mount Olivet was only five furlongs from Jerusalem, and Bethany was fifteen furlongs. However, on the eastern slope of the mountain, the tract of country was called, for a considerable area, the region of Bethany, and it was from this place that the Lord Jesus ascended.