Albert Barnes Commentary Acts 20:16

"For Paul had determined to sail past Ephesus, that he might not have to spend time in Asia; for he was hastening, if it were possible for him, to be at Jerusalem the day of Pentecost." — Acts 20:16 (ASV)

To sail by Ephesus. The word by in our translation is ambiguous. We say to go by a place, meaning either to take it in our way, to go to it, or to go past it. Here it means the latter. He intended to sail past Ephesus, without going to it.

For he hasted, etc. Had he gone to Ephesus, he would probably have been so delayed in his journey that he could not reach Jerusalem at the time of Pentecost.

The day of Pentecost. See Barnes, Acts 2:1.