Mark 16:17, which records the instructions of Christ to the apostles, including his description that "they will speak with new tongues" as a sign that would follow "them that believe" in him. Acts 2, which describes an occurrence of speaking in tongues in Jerusalem at Pentecost, though with various interpretations. Specifically, "every man heard them speak in his own language" and wondered "how hear we every man in our own tongue, wherein we were born?"