Mongolian Lha ᡀ

Lha is the thirty-third letter of the alphabet and writes the voiceless lateral of Tibetan, the sound that opens the Tibetan word for a god. Mongolian does not have it. Unicode encodes the letter at U+1840. It is the clearest single case in the alphabet of a letter added for one language's sake, and the word it is named for tells you which language and which subject matter: the transcription of Tibetan Buddhist vocabulary, in which divine and honorific terms built on that word are constant. A voiceless lateral is an unusual sound outside a handful of language families, and Tibetan is the source of nearly every Mongolian word containing one. As with the other added letters, the shape is an adaptation of a letter already present, in this case the native lateral.

The letter is a compact illustration of how a religious tradition reshapes a writing system: not by changing how the language is written, but by adding what is needed at the edges so that the vocabulary of the tradition can be set down correctly in the tradition's own terms. It stands thirty-third in the recited order, among the last of the additions and immediately before the two letters that serve Chinese syllables. Its presence also settles a question a reader might otherwise ask about the added group, which is whether the ten letters were supplied for one language or for several: this one is Tibetan, two are Chinese, and the aspirate serves Sanskrit through Tibetan spelling.

The Tibetan word this letter is named for means a god, and it is one of the most productive elements in Tibetan religious vocabulary, appearing in the names of deities, in titles, in terms for temples and images, and in the Tibetan name for the city that is the seat of the tradition. A Mongolian text on Buddhist subjects meets it constantly, and meets it in proper names where an approximation would be unhelpful. Naming a letter after a word is not unusual in itself, since most alphabets name their letters after something, but naming a letter after a word in a different language is a strong statement about what the letter is for.

Mongolian Buddhism took its vocabulary, its curriculum and much of its liturgy from Tibetan sources, and monastic education was conducted with Tibetan texts alongside Mongolian ones. The letters at the end of the alphabet are the residue of that relationship in the writing system itself. They are also a reminder that the traditional Mongolian script has never been only a secular instrument: the largest body of text it has ever carried is religious, and parts of the alphabet exist only because of it. Naming the letter after the word also fixed a convention: the added letters are known by what they are for rather than by any inherited letter name, which is one more way the recited alphabet marks its own seam between what was borrowed and what was built.