The word תַּחַת is used both as a common noun (Num. 33: 26, 27) as well as a proper noun (1 Ch. 6:4) in the Bible. in Genesis 1:7 however the difficulty I am having is that the word תַּחַת (noun) prefixed to the preposition מִן gives the idea that תַּחַת must be the noun in the accusative. My confusion and question is whether the word “under” (preposition in English) is a proper translation for the noun תַּחַת and since תַּחַת is a noun how do we understand its nature?
This was studied by Chip Hardy in his 2014 dissertation Diachronic Development in Biblical Hebrew Prepositions: A Case Study in Grammaticalization. In section 2.3.12 he distinguishes five meanings of this root:
- Noun ('place', e.g. Lev. 14:42, 'they shall take ... and put them in the place of the [diseased] stones')
- Adverb ('below', e.g. Gen. 49:25, 'He will bless you .. with the blessings of the deep lying below')
- Preposition ('under', e.g. Josh. 24:26, 'He brought a large stone and erected it there, under the oak')
- Preposition ('instead', e.g. Exod. 21:23–24, 'he shall give life for life, eye for eye, tooth for tooth')
- Preposition of cause (e.g. 1 Sam. 24:20, 'May YHWH reward you for what you have done for me today')
It is cross-linguistically common for nouns identifying places to develop into adverbs and spatial prepositions, and for spatial prepositions to develop into more abstract prepositions. This is visible everywhere, for instance, English for and foreground share a common root.
Furthermore, מִן can combine with other nouns and prepositions to form compound prepositions (hence also מִפְּנֵי 'from the presence of' in Gen. 3:8, for instance). Whether you analyse these as PREP+PREP or PREP+NOUN does not really matter for their function; it is clear that they are compound prepositions.