Perhaps from an unused root meaning to stand out, or exist; entity; used adverbially or as a copula for the substantive verb (
hayah); there is or are (or any other form of the verb to be, as may suit the connection) -- (there) are, (he, it, shall, there, there may, there shall, there should) be, thou do, had, hast, (which) hath, (I, shalt, that) have, (he, it, there) is, substance, it (there) was, (there) were, ye will, thou wilt, wouldest.
see HEBREW hayah