number. Greek. ochlos, crowd. This is an occurance of the Figure of speech Epitrechon.
together = to the same (place). Greek. epi to auto. See Act_2:1, Act_2:44; Act_4:26. 1Co_7:5; 1Co_11:20; 1Co_14:23.
an hundred and twenty = three forties. A divinely appointed number during a period of waiting. It -was the number of Ezra's great synagogue. See App-10.