I was trying to figure out if and how made (until) and ma (place, gap) were related when, in the Nihon gogen daijiten, I ran across this bold hypothesis regarding the origin of ma itself:

天から出た語か（和訓栞）
"Word that came out of heaven?"

This is attributed to Wakun no shiori, "A guide to Japanese readings [as opposed to Chinese ones]", a book published by TANIKAWA Kotosuga (谷川士清) in the late 1700s. NGD says that it is generally considered Japan's first etymological work in a modern(ish) style.

I am curious about how closely Tanikawa's actual words match what is attributed to him here. Obviously, the intended meaning is "there is no deeper root beneath ma", but did he actually use the word 天 (heaven)? And if so, how figuratively did he mean it? I know that the idiom ten kara ("from heaven") is still found in modern Japanese meaning "from the start" or "all along", although I mostly see it in negative sentences like 天から信じてない, "[I] never trusted [that guy]".