old
gods as a preservative against this corruption. Hence the Law
prescribed such houses, where this kind of corruption was of a
lasting nature, to be destroyed; and such garments to be burnt, in
order to avoid all occasion of idolatry. There was also an
uncleanness of vessels, of which it is written (Num. 19:15): "The
vessel that hath no cover, and binding over it, shall be unclean."
The cause of this uncleanness was that anything unclean might easily
drop into such vessels, so as to render them unclean. Moreover, this
command aimed at the prevention of idolatry. For idolaters believed
that if mice, lizards, or the like, which they used to sacrifice to
the idols, fell into the vessels or into the water, these became more
pleasing to the gods. Even now some women let down uncovered vessels
in honor of the nocturnal deities which they call "Janae."

The figurative reason of these uncleannesses is that the leprosy of a
house signified the uncleanness of the assembly of heretics; the
leprosy of a linen garment signified an evil life arising from
bitterness of mind; the leprosy of a woolen garment denoted the
wickedness of flatterers; leprosy in the warp signified the vices of
the soul; leprosy on the woof denoted sins of the flesh, for as the
warp is in the woof, so is the soul in the body. The vessel that has
neither cover nor binding, betokens a man who lacks the veil of
taciturnity, and who is unrestrained by any severity of discipline.

Reply Obj. 5: As stated above (ad 4), there was a twofold uncleanness
in the Law; one by way of corruption in the mind or in the body; and
this was the graver uncleanness; the other was by mere contact with
an unclean thing, and this was less grave, and was more easily
expiated. Because the former uncleanness was expiated by sacrifices
for sins, since all corruption is due to sin, and signifies sin:
whereas the latter uncleanness was expiated by the mere sprinkling of
a certain water, of which water we read in Num. 19. For there God
commanded them to take a red cow in memory of the sin they had
committed in worshipping a calf. And a cow is mentioned rather than a
calf, because it was thus that the Lord was wont to designate the
synagogue, according to Osee 4:16: "Israel hath gone astray like a
wanton heifer": and this was, perhaps, because they worshipped
heifers after the custom of Egypt, according to Osee 10:5: "(They)
have worshipped the kine of Bethaven." And in detestation of the