Moed Katan, Chapter One, Mishnah Eight
This mishnah deals with sewing on the festival. It introduces a principle which we have not yet seen in the previous mishnayot. There are certain types of labor that may be done by a non-professional but not by a craftsman. This prevents professionals from working on the festival, while still allowing ordinary people to engage in light labors.
1) An ordinary person may sew in the usual way, but a craftsman may sew [only using] uneven stitches.
2) And they may weave the ropes of a bed.
a) Rabbi Yose says: they may even be tightened.
Section one: An ordinary person can sew in a normal way, assuming he has an immediate need to do so. Sewing is not a heavy labor, and therefore it is permitted on the festival.
However, a professional craftsman cannot sew in a normal way because that would allow him to engage in his profession during the festival. This is prohibited even if he is not paid for the work. The mishnah allows him to make some sort of uneven stitches. This might allow him to fix things that need to be fixed while still preventing him from engaging in his normal profession.
Section two: In the mishnaic period beds were made with a frame around which they would loop ropes. The tighter the ropes, the firmer the bed (this is the origin of the phrase sleep tight). The mishnah allows a person to weave ropes around the frame of a bed because this is not a significant amount of work. It is also necessary if one wants to sleep on a bed.
There are two versions of Rabbi Yoses statement. According to the version which I have translated he even allows ropes that are already on the bed to be tightened. We might have thought that since the ropes were already there that tightening them is not really necessary and hence forbidden on the festival. In this version, Rabbi Yose is more lenient than the previous opinion.
According to the other version, Rabbi Yose only allows tightening ropes and not weaving ropes that are not already attached to the bed frame. In this version Rabbi Yose is stricter.