Vincent's NT Word Studies
16. Into the hall called Pretorium. Mark, as usual, amplifies. Matthew has simply the Pretorium. The courtyard, surrounded by the buildings of the Pretorium, so that the people passing through the vestibule into this quadrangle found themselves in the Pretorium.Band (speiran). Originally anything wound or wrapped round; as a ball, the coils of a snake, a knot or curl in wood. Hence a body of men-at-arms. The same idea is at the bottom of the Latin manipulus, which is sometimes (as by Josephus) used to translate speira. Manipulus was originally a bundle or handful. The ancient Romans adopted a pole with a handful of hay or straw twisted about it as the standard of a company of soldiers; hence a certain number or body of soldiers under one standard was called manipulus.
Robertson's NT Word Studies
15:16 {The praetorium} (praitwrion). In #Mt 27:27 this same word is translated "palace." That is its meaning here also, the palace in which the Roman provincial governor resided. In #Php 1:13 it means the Praetorian Guard in Rome. Mark mentions here "the court" (tes aules) inside of the palace into which the people passed from the street through the vestibule. See further on Matthew about the "band."