Why we do what we do: Khathun (ཁ་ཐུན་), which literally means oral or mouth (ཁ་) sessions (ཐུན་), refers to the daily prayers which traditional Bhutanese elders chant. People chant their prayers mostly early in the morning and/or late in the evening. Because the prayers are chanted at specific times and sessions, they are known as thun or sessions. Like the Book of Hours in medieval Christian traditions, books of prayers called thunpe (ཐུན་དཔེ་) or Book of Sessions and Choechod (ཆོས་སྤྱོད་) or Religious Practices are compiled containing the common prayers according to different traditions.
In Bhutan, the common thunpe or choechod follows the Kagyu or the Nyingma tradition of Vajrayāna Buddhism. They start with the liturgies for the preliminary practices which sometimes begin with supplication to one’s guru known as calling the lama from afar (བླམ་རྒྱང་འབོད་). The liturgies for preliminary practices are followed by several literary compositions in praise of the Buddha. These are followed by the praises of and supplication to Guru Rinpoche, the main figure who introduced Buddhism to Bhutan, the prayers to the lamas of the religious line including Zhabdrung Ngawang Namgyal, the founder of Bhutan.
The thunpe contains praises and prayers to many other Buddhas and Bodhisattvas and also includes short sūtras such as The Heart Sūtra and The Sūtra for Longevity. Towards the end, it also contains a large number of aspirational prayers (སྨོན་ལམ་) associated with different Buddhas. Besides chanting these prayers regularly, Bhutanese chant these prayers in groups as part of funerary ceremonies. The collection of khathun may also contain as appendices liturgies for various different purposes such as the verse chanted before tea, before meal, before snacks, the prayers chanted before making a serkem (གསེར་སྐྱེམས་) or alcohol offering, the chants for making the sang (བསངས་) incense and smoke offering, the prayers chanted for making the sur (བསུར་) smell offering, etc.
Most older Bhutanese occupy themselves in the morning and evening with their khathun. They chant some of the prayers only once but they may have an individual prayer or khathun which they chant over and over again. Many of them would chant the prayers from memory and it is not uncommon to find a traditional elder who is illiterate and yet very well versed in many types of khathun. Bhutanese believe that chanting the khathun regularly helps them avoid harm and misfortunes, achieve their wishes, live longer and healthier lives, accumulate merit for a better rebirth, and also help them reach enlightenment swiftly.