Commanded (prosetaxen). First aorist active indicative. Peter himself abstained from baptizing on this occasion (cf. Paul in 1Co 1:14). Evidently it was done by the six Jewish brethren.
Them to be baptized (autous baptisthēnai). Accusative of general reference with the first aorist passive infinitive.
In the name of Jesus Christ (en tōi onomati Iēsou Christou). The essential name in Christian baptism as in Act 2:38; Act 19:5. But these passages give the authority for the act, not the formula that was employed (Alvah Hovey in Hackett’s Commentary. See also chapter on the Baptismal Formula in my The Christ of the Logia). “Golden days” (aurei dies, Bengel) were these for the whole group.