Sun = 'eye of the day'

Matthias Urban, in 2010, presented a paper discussing the way some Asian languages describes the Sun as 'eye of the day'. In Malay, the Sun is mata hari in which mata means 'eye' and hari means 'day'. Proto-Austronesian etymon for 'sun' is reconstructed as *maCa nu qalejaw. In Tai languages, it generally is expressed as ta van where ta means 'eye' and van means 'day'. He noted that according to data from 'The world atlas of language structures' the occurence of this phenomenon is remarkably restricted areally. This phenomenon occurs only in Southeast Asia and the Pacific where Austronesian languages are spoken. The only language outside these areas that exhibits the same pattern is San Mateo Del Mar Huave, a language isolate of Mexico, where ‘sun’ is teat nüt, literally ‘father of the day’. Tetum, an Austronesian language belonging to Central Malayo-Polynesian branch that's spoken in East Timor, has the simplex term loro for ‘sun’, on the basis of which an optional, and seemingly semantically redundant, compound loro-matan ‘sun-eye’ is formed.

Data from the world atlas of language structures

After collecting more data for Austroasiatic family from the Mon-Khmer comparative dictionary, for Austronesian from Tryon (1995b) including Austronesian languages of Taiwan (“Formosan languages”), for Tai-Kadai languages from L-Thongkum (1994) and for Hmong Mien languages from extant dictionaries, he came up with the following map:

In the Tai-Kadai language Nung Fahn Sling, the Sun has its form as phἀ vahn, literally ‘cover day’. And in other Nung languages, the Sun is expressed as tha van, literally means 'eye of the day'. To explain this wide but geographically contiguous distribution, Urban considered four historical scenarios:

1. The Southeast Asian and Austronesian cases are historically independent.
2. The expression developed in mainland Southeast Asia either through diffusion or common origin when the ancestral communities for all three language families were in closer contact or formed a single language-community.
3. The expression was innovated in Proto–Malayo-Polynesian (PMP), the ancestor of the non-Formosan AN languages, and then spread into mainland Southeast Asian languages through contact with Chamic or Malay.
4. The expression was innovated in mainland Southeast Asia (“possibly Austroasiatic”), and was then borrowed into PMP.