When the Chinese pilgrim monk, Songyun, visited the region in 518, he noted that the people had a written language, which was more than a hundred years before Thonmi Sambhota is said to have returned from India after developing a script for writing the Tibetan language.
Da den kinesiske pilgrimsmunk, Songyun, besøgte regionen i 518, bemærkede han, at folket havde et skriftligt sprog, som var mere end hundrede år før, at Thonmi Sambhota siges at være vendt tilbage fra Indien efter at have udviklet en skrift til at skrive det tibetanske sprog.