{Stood by him} (epest(885c)). Ingressive second aorist active
indicative of ephist(886d)i, intransitive. This very form occurs in
 Lu 2:9  of the sudden appearance of the angel of the Lord to the
shepherds. Page notes that this second aorist of ephist(886d)i
occurs seven times in the Gospel of Luke, eight times in the
Acts, and nowhere else in the N.T. Note also the same form
apest(885c) (departed from, from aphist(886d)i, stood off from) of the
disappearance of the angel in verse  10 . {In the cell} (en t(9369)
oik(886d)ati). Literally, a dwelling place or habitation (from
oike(935c), to dwell, oikos, house), but here not the prison as a
whole as in Thucydides, but the room in the prison (cell) where
Peter was chained to the two guards. Old word, but only here in
the N.T. {He smote Peter on the side} (pataxas t(886e) pleuran tou
Petrou). More exactly, "smote the side of Peter." Strongly
enough to wake Peter up who was sound asleep and yet not rouse
the two guards. It was probably between 3 A.M. and 6 A.M., hours
when changes in the guards were made. {Rise up} (anasta). Short
form (_Koin(825f)) of anast(8874)hi, second aorist active imperative of
anist(886d)i, intransitive. So also  Ac 9:11  (Westcott and Hort
text);  Eph 5:14 . {Fell off} (exepesan). Second aorist active
with a ending like first aorist of expipt(935c), old verb. This
miracle was necessary if Peter was to escape without rousing the
two guards.