Verse 12: Technically the feast of unleavened bread immediately followed Passover, but by this period popular usage counted the Passover as part of the larger unleavened bread festival. Representatives from each household would have the lamb sacrificed at the temple, and the household would eat the meat that night.
13: Commentators often observe that, in contrast to leather wineskins, water jars were usually carried by women (often the matron of the home); thus a man doing so would be unusual enough to be recognizable. In well-to-do households (as apparently here), slaves would carry the water; running water was a great luxury, and in many cities people would collect water at public fountains.
14: People wanted to eat Passover within the city limits, so they often sought local hospitality, often leading to crowded accommodations, except in well-to-do homes (as apparently in 14:15).
15: Unless the house was unusually large (some were), the upper room would provide an intimate environment for just a few disciples (say, the Twelve; not many more). This house was presumably of significant size to support an upper room large enough even for twelve to recline. This suggests that this was a spacious home, apparently in Upper City Jerusalem (as opposed to the poorer Lower City, downwind of the sewers).
17: The Passover had to be eaten at night; because sundown came by about 6 p.m. in Jerusalem in April, they could have begun the meal at that time. Normally one or two families banded together to eat the lamb; here Jesus and the twelve function as a family unit.
20: Dipping bowls were particularly used at Passover; the dish here is probably Passover’s dish of bitter herbs. Hospitality and table fellowship established a covenant of friendship; to betray a former host or guest, much less a current one, was considered among the most despicable acts of treachery.
Some scholars suggest that dipping “with” Jesus could imply rebellion, since (as in the Dead Sea Scrolls) the leader should act first, and many ancient banquets seated people by rank. This interpretation would be likeliest if Judas reclined near Jesus, on the same couch (cf. Jn 13:26).
21: Various biblical passages (Job 3:3-26; Jer 20:14-18), early Jewish and Greek lamentations spoke of never having been born alive being preferable to selected worse fates.
(Adapted from Dr. Keener’s personal research. Used with permission from InterVarsity Press, which published similar research by Dr. Keener in The IVP Bible Background Commentary: New Testament. Buy the book here.)