A question arises here: have we to read l(e) or la? l(e)maHatsit or lamaHatsit?
Answering to this is not difficult.
If we consider that our word is in the construct because of a noun following it and depending on it, we know that this first noun takes no article. That is, preposition ל lacks article, that's why it must be read l(e) and not la.
Bible has this noun with nothing at its front: Exo 30:13.