בבא בתרא דף יב ע"ב
א"ר יוחנן מיום שחרב בית המקדש ניטלה נבואה מן הנביאים וניתנה לשוטים ולתינוקות
Bava Batra 12b
Ribbi Yochanan says: Since the day that the Bet Hamikdash was destroyed, prophecy was taken away from the nevi'im and given instead to the psychotic and small children.
A"A says that if anyone ever claims to you that he received a prophecy, you can be confident that he is either lying or mentally ill.
