Question:

It says in Deut12:21 “…you may slaughter from your cattle and your
flocks that the Creator has given you, as I have commanded you, and you
may eat it in your cities…”.
The question is: This verse explicitly says that animal slaughter shall
be done in the manner “as I have commanded you”, yet the commands of
proper animal slaughter can not be found in all of scripture. Such
commands do not exist in the written scriptures. The argument therefore
concludes: This verse is making reference to a set of non-written, oral
commands given along with the written Old Testament which enable this and
similar versus to be understood and applied.

Answer:

I agree with your conclusion, but I do not agree with your reasoning to
reach this conclusion. Let me explain. The writer of Deuteronomy says
that the Jews should slaughter thier cattle or other animals as he had
commanded them. You say that the scripture does not specify how to
slaughter, but I do not agree with this. In fact, just a verse or two
below God gives specific instructions about how to slaughter animals. In
verse 23-24 he tells them that they must not eat the blood. In addition,
they must slaughter the cattle in such a way that the blood drains out on
the ground. Here is a specific command as to how to slaughter. They were
not to club the animals to death or to strangle them, but to kill them in
a way which drains the blood. I am assuming that they were to cut them at
the neck.

Nevertheless, I believe that there almost certainly were other oral
commands given to the Jews. As an analogy there were also commands which
the apostles passed on to the early church which were not included in the
New Testament. We know that Paul wrote some letters which are not
included in the New Testament. I assume that this is because some of the
instructions were expedient for the time and were not intended as commands
for all time. Actually, except for the Ten Commandments, all the laws
were given “orally” to Moses, although we can assume that many or most of
them were written down in the form we now have, including the laws in
Leviticus and in Deuteronomy. So, I agree with your thesis that it is
very likely that God spoke commands to the Jews at Sinai which were not
written down. However, I do not believe that the particular example you
give provides support for this conclusion. I hope this response makes
sense to you.

John Oakes,PhD