The main components of Tefillin are:
1) The ‘batim’ (boxes) – one for ‘shel yad’ (hand tefillin) and one for ‘shel rosh’ (head tefillin) 2) The ‘retzuos’ (straps) – also one for each 3) The ‘klaf’ (parchments) – upon which the four ‘parshios’ (i.e. paragraphs from the Torah) are written and then placed inside the tefillin, both the ‘shel yad’ and the ‘shel rosh’
The remainder of this siman deals primarily with the ‘batim’. (Ed: Please note that we are starting with paragraph 37 of this siman. We are skipping the halachos of the writing of the ‘parshios’, as they are beyond the scope of this forum – and my scope!)
Question: Fact: All of the materials of the tefillin are taken from animals (except for the ink). (Did you know that?) From what kinds of animals can tefillin be made?
Answer: The Torah states (Shmos 13:9): “And it (i.e. tefillin) will be for you for a sign on your hand and for a remembrance between your eyes – so that Hashem’s Torah may be in your mouth…” From the juxtaposition between the tefillin and “your mouth”, the Sages derive an allusion to the halacha that tefillin must be made from any animal, as long as it is kosher – i.e. an animal that you could put, literally, in your mouth! This does not require that the animal be slaughtered according to ritual law; merely that it be of a kosher species. (Chicken-skin tefillin, anyone? It’s kosher, you know!)
There is another standard requirement in the making of tefillin (and some other mitzvah objects as well), namely that it be prepared ‘lishmah’ (lit. for its sake). This means that one is not permitted to take hide that was processed for some other purpose and use it for the ‘batim’, ‘retzuos’ or ‘klaf’. The hide must have been processed – from the point of tanning – for the sake of making tefillin. (Note: There are grounds for a leniency in certain cases with regard to the hide for the ‘batim’ only.)