{They heard} ((886b)ouon). Imperfect active, were hearing,
kept on hearing. {Speak} (lalount(936e)). Present active
participle, speaking, for they kept it up. {With tongues}
(gl(9373)sais). Instrumental case as in  2:4,11  which see. The
fuller statement there makes it clear that here it was new and
strange tongues also as in  19:6  1Co 14:4-19 . This sudden
manifestation of the Holy Spirit's power on uncircumcised
Gentiles was probably necessary to convince Peter and the six
brethren of the circumcision that God had opened the door wide to
Gentiles. It was proof that a Gentile Pentecost had come and
Peter used it effectively in his defence in Jerusalem ( Ac
11:15 ).