The story is told that when the students of Rav Yisrael Salanter were preparing to bake matzah, they asked Rav Yisrael what they should be most careful about. Rav Yisrael, the founder of the Mussar movement, responded that they should ensure that the water buckets that the workers would have to carry for the baking of matzah should not be heavy. Worrying about possible chametz is important; worrying about the workers even more so.
One of the key distinctions between the land of Israel and the Diaspora is the ability to observe the many mitzvot between man and the land. The seventh chapter of Yevamot focuses on the intricacies of the laws of terumah, which may be eaten only by a kohen or a member of his household. The chapter begins by analyzing the case of a kohen marrying someone prohibited to him, such as a divorcee.
Immediately after the Divine revelation at Sinai, the Torah in Parshat Mishpatim presents a long list of mitzvoth, highlighting the link between Torah and mitzvoth. G-d's covenant with the Jewish people is based on commandments that we must fulfill.
Yet as is so typical of Jewish thought, one idea is followed by an opposing one. The centrality of obligation is immediately followed by one highlighting the great role of the volunteer. "Speak to the children of Israel and take for me a portion from everyone whose heart motivates him" (Shemot 25:2).
Soon after the editing of the Mishna in the land of Israel, Jewish life and learning started slowly shifting towards Bavel. This was set into motion by Rav and Shmuel two of the leading students of Rabbi Yehuda Hanassi - the editor of the Mishna - who headed the great Babylonian learning centres of Sura and Neharda and was exacerbated by the increasingly difficulty of religious life in Israel. There was much interaction between these two great centres as leading rabbis would travel back and forth bringing the teachings of one to the other.
Both an eiruv techumim, which allows one to walk an additional 2,000 cubits (approximately 1 kilometre) outside of the city limits, and an eiruv chatzerot, which allows us to carry on Shabbat, require the placement of food in a designated spot. The food must be edible, a requirement that would exclude tevel, food from which tithes (terumah and ma'aser) were not taken.
At times, what seems like a very technical debate on some (even no longer relevant) aspect of Jewish law is, in reality, part of much larger and more fundamental debate about a key aspect of Jewish thought.