The Binding of Tongues is old witch magic, which evolved from that most ancient caste of practitioners known throughout history as the School of Entwiners
The witches of Karaam-Sava were, and some say still are, most known for brandishing this form of arcana.
Thousands of years ago, tongue-binding magic was used by the witches to thwart the pygmy armies of the Gwa and their vile Spell-Throats.
Centuries later, during the Ebn-Nodd Imperium (the empire of the Sons of Nodd), these same witches, or more accurately, their descendants and apt pupils, used tongue-binding magic in battling back the relentless assaults of the magicians of Uo, who came from their hilly, eastern lands, riding their malevolent winged, devil-goats, in brazen attempts to assassinate the Potentates and Imperators of Karaam-Sava, in retaliation for the years of rapine and pillage the people of Uo had suffered and endured, during Ebn-Nodds empirical expansion.
In essence, Tongue-Binding involved the silencing of spell casters via the laws of Contagion Magic