This phrase may modify either the expression “the doors were shut” or the expression “the disciples were assembled.” The Greek construction and context both favor the former. The place where they were assembled was the upper room where they had celebrated the Passover (see Luke 24:33). It seems unlikely that the disciples would have sought concealment in a place so well known as this. However, to have the doors barred against enemies is perfectly understandable (cf. DA 802). The following translation illustrates such a relationship between the clauses, “the doors where the disciples were assembled were shut for fear of the Jews.”

That is, Roman time, which reckoned the days as beginning at midnight. According to Jewish time, which reckoned the day as beginning at sunset, the meeting took place on the second day of the week.

 [First Appearance in the Upper Room, John 20:19-23=Mark 16:13=Luke 24:33-49. Major comment: Luke and John. See See The Resurrection and Subsequent Events; the Resurrection to Ascension.] This meeting is doubtless the same as that described in Luke 24:36-48. The meeting took place after the two disciples returned from Emmaus, which was late at night (see on Luke 24:33).