In parsha Shemini we discuss what goes into our mouths
Maachalos Asuros, the different categories of kashrus of things we can
and cannot eat. Many people dont understand kashrus they ask what does
G-d care what you eat? But that truth is You are what you eat.
Literally. Your physical body is made up of the building blocks from the
food you consume. The Torah tells us that this has a an effect on our
souls as well. Read not as veNitmesim Bam - that it defiles you, but
rather veNitamtem Bam - that it clogs your mind and heart. The Baal Shem
Tov's grandson, the author of Degel Machne Efraim (Ekev) says that his
grandfather's great disciple, the Toldos Yaakov Yosef quotes an amazing
Teshuvas HaRambam, it seems that a community questioned the Rambam on
the authenticity for Chazal's mesora for our traditional belief of
resurrection and techuyas hamesim, they scoffed at the proofs brought.
The Rambam chastised them and wrote back that surely their apikorsus and
disbelief stemmed from the fact that they ate forbidden foods and the
non kosher food had meddled with their minds and clogged their hearts!
Next in Tazria we read about the Metzora who is afflicted for what comes out of his mouth namely Lashon HaRa.
Both these Parshas follow Pesach a YomTov whose Name (according to the
AriZal) means Peh Sach - the speaking mouth. In fact all of the mitzvos
connected are done with our mouths. Eating the matzah (during beis
hamikdash of the korban Pesach), the marror, the karpas and charroses,
drinking the 4 cups of wine and retelling the Sippur Yetziyas Mitzraim
of the Exodus from Egypt. Even counting Sefiras HaOmer which begins on
night 2 of Pesach - all done with the mouth.