Devadaha is a Sakyan town mentioned in a few suttas (MN 101, SN 22.2, SN 35.134). It became famous in later Buddhism as the birthplace of the sisters Māyā and Mahāpajāpatī of the Koliyan clan, the Buddha’s birth mother and foster mother. These details are not mentioned in early texts, however, where the town is said to be Sakyan rather than Koliyan. It is identified with Devdaha in the Rupandehi District of Nepal.
The name is explained in the commentary as “royal lake”, taking deva- as a term for kings, and -daha as equivalent to the Sanskrit draha (or hrada), a rare word for “lake”.
However, it is spelled devadṛśa in the Mūlasarvāstivāda Vinaya (San Mu Kd 17:6). Dṛśa means “sight, appearance”, thus occupying a completely different semantic space than “lake”. This is problematic, as it raises the question as to how such a confusion could arise. Is there any connecting tissue between these readings?
Dṛśa is a Vedic term that commonly describes Agni’s fiery gleam (Rig Veda 3.17.4, 6.10.4, 7.1.1, etc.). Here is a typical usage, from Jamison/Brereton’s translation of 3.17.4:
Singing to Agni, the one beautifully shining, beautifully appearing,
we revere you who are to be invoked, Jātavedas.
You have the gods made the messenger, the spoked wheel (of flames),
the conveyor of oblations, and the navel of immortality.
Since the Sanskrit word depicts the shining of a flame, it suggests we should derive daha from the Pali root √ ḍah, “to burn”. Note that the initial ḍ here exhibits instability with d. In fact the Hybrid Sanskrit form in the Mahāvastu is devaḍaha. This is explained in the Buddhist Hybrid Sanskrit dictionary in line with the Pali commentarial derivation, “daha for Skt. Lex. draha = Skt. hrada”, but the entry doesn’t notice the Sanskrit form.
Thus we have direct textual support for the form devaḍaha, for which the Pali sense is “blazing of the gods”.
This recalls Śatapatha Brāhmaṇa 1.4.1.14–16, which allegorically depicts the spread of Aryan culture eastward as Agni “burning” (dadāha) the lands, i.e. introducing the civilized practice of Vedic fire worship.
Māthava, the Videgha, was at that time on the (river) Sarasvatī[8]. He (Agni) thence went burning along this earth towards the east; and Gotama Rāhūgaṇa and the Videgha Māthava followed after him as he was burning along. He burnt over (dried up) all these rivers. Now that (river), which is called ‘Sadānīrā,’ flows from the northern (Himālaya) mountain: that one he did not burn over. That one the Brāhmans did not cross in former times, thinking, ‘it has not been burnt over by Agni Vaiśvānara.’
Now-a-days, however, there are many Brāhmans to the east of it. At that time it (the land east of the Sadānīrā) was very uncultivated, very marshy, because it had not been tasted by Agni Vaiśvānara.
Now-a-days, however, it is very cultivated, for the Brāhmans have caused (Agni) to taste it through sacrifices. Even in late summer that (river), as it were, rages along[9]: so cold is it, not having been burnt over by Agni Vaiśvānara.
The lands spoke of here would appear to be the Gandaki river (= Sadānīra?) and Videha (= Videgha), which lies to the east of Sakya/Koliya. The Gandaki formed the eastern border of the Koliyan republic.
Thus the Brahmana, composed some centuries before the Buddha, is speaking of the spread of Vedic culture by “burning” the lands eastward, which, judging from the name Devadaha, would include the Sakyan/Koliyan lands.
The concept of “burning” seems to include the changing of the nature of the lands, drying up marshes and the like. The worship of Agni was, it seems, associated with burning the land to clear it for agriculture.
I think the meaning of devadaha is, therefore, “burned by the god”, or “place of the god’s flame”, indicating that the land was Aryanized by Vedic worship. This agrees with the fact that the Sakyan leading clans are called Gotama, which is the brahmanical clan name of the high priest, adopted in the anointment ceremony.
Just to be clear, however, the fact that the royal clans sought Brahmanical authority for their royal aspirations does not mean that the people uniformly followed “Vedic” religion. Religion in India has always been a complex mix of different things.