There were many lights; there being many present; and it being in the night, because of the persecution that the Christians met with. Lest they should be reproached for doing any thing indecently, they by this means exposed themselves, and all that was done amongst them, to the common view and notice of all. In the upper chamber; where it is supposed they did ordinarily meet; as Acts 1:13.
Related Commentaries of Acts 20:8
Acts 20:8
8 And there were many lights in the upper chamber, where they were gathered together.