Receiving communion on the tongue is a liturgical aberration which the church continues to tolerate, but it is at odds with the practice of the early church. The ancient practice is is well-described in this instruction by St. Cyril of Jerusalem (d. 386):
 "When you approach, take care not to do so with your hand stretched out and your fingers open or apart, but rather place your left hand as a throne beneath your right, as befits one who is about to receive the King. Then receive him, taking care that nothing is lost."