Tongues

Boyd’s Bible Dictionary:

“And the whole earth was of one language, and of one speech”
(Gen. 11:1). Confusion of tongues and dispersion of peoples coincident (Gen. 11:7-9). “New tongues” (Mark 16:17), is the first notice of a gift specially characteristic of the first outpouring of the Spirit. Ten days afterward the promise was fulfilled in the Pentecostal phenomenon (Acts 2:1-13).