Several factors can cause food to be non-kosher, here a short explanation about four main factors: non-kosher ingredients, mixing of meat and milk, food cooked by a Gentile, and a set time when a food is forbidden.
In the process of leaving Egypt and becoming a nation we distinguish between the initial state which stands for itself, the goal at the end which stands for itself and the process.
Even if a person sins, even if it's one of the worst sins, being close to a prophet affects him. Although there was the sin of the golden calf, when there is communication between Moses and the nation, they can still learn from him without being afraid of the light shining from his face.
Aaron wears the names of Israel, the Urim and the Thummim and shall bear the judgment of the children of Israel on his heart. What's the special emphasis and conection between the Hoshen and the heart and what are those three things that Aaron has upon his heart?
They are two "faces", or view points to the Cherubim, a baby face who is completely dependent on his mother, and a couple with a great affection between them.
Yitro heard of all that God had done for Moses and the nation, so he came to the wilderness. What did Yitro hear? What caused him to leave his home and go to the wilderness? What happened that he couldn't be indifferent?
One of the Korban Pesach laws is that apostate Jews may not eat the Korban. Why on other holidays we accept even Jewish criminals, but on Pesach the Torah forbade those people who cut themselves off from the nation from eating the Pesach lamb?
Moshe Rabenu, sent to take Am Yisrael out of Egypt, asks G-d how will Pharaoh listen to him if Israel didn't. This claim teaches us about the importance of Israel in bringing G-D's words into actual life.