One may temporarily repair/replace the rope of a bucket in a well, but not by replacing it with a rope and knot that could become permament. Rabbi Yehuda disagrees with Rabbi Meir and holds that a bow knot is a genuine knot because it could become permanent. Now we come to a discussion that could’ve opened our study of Shabbos, and we learn how Shabbos differs from the rest of the week in principle. We don’t just abstain from the prohibited labors – we need to make the day different all together. We don’t fold clothes or make our beds or discuss work, because we don’t prepare on Shabbos for the acitivities of the week. We make our speech, clothes, thoughts and even our manner of walking different on Shabbos. And by definition, here in Mishnah 4 of Chapter 15, we learn that Shabbos is holier that Yom Kippur, and is thus the holiest day of the year. Thank you God for sending the holiest day of the year every seven days!