Bai sema

Bai sema (Thai: ใบเสมา, pronounced [bāj sěː.māː]) are boundary stones which designate the sacred area for a phra ubosot (ordination hall) within a Thai Buddhist temple (wat); otherwise called sema hin (เสมาหิน).
History
It is written in the Vinaya Pitaka that the Baddhasima (the area in which the monks perform the Sanghakamma or Buddhist sacred ceremonies) must be able to accommodate 21 seated monks, with a space the length of a forearm between each monk. The area should also not be larger than three yojana which is about 48 kilometres (30 mi). This is probably meant to mean the maximum circumference. In other words, the Baddhasima should not be too small, nor too big.
It is also written that the Baddhasima can be marked by the following Nimitta (border markers): hills, rock formations, forests, trees, ant hills, streets, rivers and other waters such as the sea or a pond. The type of Nimitta that is mainly used in Thailand is a stone. The oldest stone bai sema in Thailand were found in northeast Thailand (Isan) and are from the Dvaravati period (6th - 9th century CE).
The chronology of these early stones is disputed, and the disagreement bears on the historical questions they have been used to settle. Rungrot Phiromanukun assigns the first sets of ritual boundary stones generally to about 600–750; Jean Boisselier placed the numerous stones at Mueang Fa Daet Song Yang in Kalasin province in about the 9th century; and Piriya Krairiksh assigned several of the figural stones from that site to the 10th.[1]: 88–89 Hiram Woodward, who reports these positions, observes that the analysis of costume and coiffure on the stones carrying narrative scenes, which might establish a firmer chronology, has not been undertaken, and concludes that the Fa Daet stones cannot on their own demonstrate that an urban centre stood in that region in the 8th century.[1]: 88–89 He had himself earlier proposed that two sets of boundary stones on Phnom Kulen in Cambodia, first published in 1973, were foundations of the polity known from Tang Chinese records as Wen Dan, but afterwards described that argument as incautious, since the stones cannot be dated closely enough to show whether they precede or follow the accession of Jayavarman II in 802.[1]: 88
A recurring motif on stones of this early group is the kumbha stupa, a stupa raised on a vessel-shaped base. Woodward records the form on boundary stones from Hin Khon in Pak Thong Chai district, Nakhon Ratchasima province, from near Muang Bon in Nakhon Sawan province, from Ban Tat Thong in Yasothon province and from Phnom Kulen, and on related objects including a bronze reliquary from Na Dun district and a silver repoussé sheet from Kantharawichai district, both in Maha Sarakham province. A terracotta kumbha from Thap Chumphon in Nakhon Sawan carries an inscription in characters of the 9th or 10th century recording in Mon that the offering was made by the ancestors near the vihāra, together with the Pali ye dhammā formula.[1]: 88
Placing of the bai sema
Before work starts on a new phra ubosot, nine holes are dug: eight at the cardinal points, the ninth beneath where the principal Buddha statue will be placed. Luk nimit (Thai: ลูกนิมิต), round stones the size of a cannonball, are placed in to these holes during a religious ceremony. Eight Sema stones are then placed over those Luk Nimit which are situated at the cardinal points. Double (or even triple) bai sema signify that the phra ubosot has been rebuilt, or consecrated for use by more than one monastic order, or that the temple has a Royal connection (photo 1).
Description of the bai sema
The Thai words bai sema mean "Sema leaves" due to the shape of the flat Sema stones being somewhat akin to the shape of the leaves of the Bodhi tree, the tree under which the Buddha achieved enlightenment (photo 1).
Parts of a bai sema are described in Thailand as being body parts: "neck", "shoulders", "chest", "hips" and "stomach". During the Ayutthaya kingdom and the following Rattanakosin era, bai sema would sometimes be decorated with eyes (photo 2) and princely crowns (photo 3). The Thammayut order, which was founded by Prince Mongkut (the later King Rama IV) in 1833, developed a three-dimensional form of bai sema (photo 4).
Gallery
Photo 2: Bai Sema with "eyes", Wat Phra Kaeo, Bangkok
Photo 3: "crowned" Bai Sema, Wat Ratchanadda, Bangkok
Photo 4: four sided Bai Sema, Wat Mahanaparam, Bangkok- Two sets of Bai Sema surround the ubosot and a chedi at Wat Chet Yot, Chiang Mai

A triple Bai Sema in Sukhothai
Gilding, Lumbini, Nepal
See also
- Cetiya
- Uposatha
- Patimokkha
- Upasampadā
- Ordination hall
- Vihara
- Visungkhamsima
- Kyaung
- Wat
References
- 1 2 3 4 Woodward, Hiram (2010). "Dvaravati, Si Thep, and Wendan". Bulletin of the Indo-Pacific Prehistory Association. 30: 87–97. Archived from the original on 15 October 2022.
Sources
- No Na Paknam: The Buddhist Boundary Markers of Thailand. Muang Boran Press, Bangkok 1981 (No ISBN, only to be had from used bookstores)
- No Na Paknam: Sima Gattha, Samut Khoi Wat Suthat Thepwararam ("Manuscript of Sima of Wat Suthat Dhepvararam"). Muang Boran Press, Bangkok 1997, ISBN 974-7367-82-3