פירוש על כלים 26:7

שיש חסרון מלאכה – that there still is lacking action, but afterwards [the thought] is actualized.

Introduction Above, in 25:9 we learned that vessels can become susceptible to impurity by virtue of the fact that a person intends to use them in their current state, even though their manufacturing has not been entirely completed. Our mishnah limits that halakhah.

העוצבה (fur trimmed of its ends, robe, cover) – even though it is missing work, the though defiles it, because they are not strict on its missing work. And עוצבה/fur trimmed of its ends, robe, cover is the hide that covers the riding seat/saddle, which doesn’t require trimming the ends of a skin, for since it is made for a cover, we don’t worry about trimming the ends of a skin.

Whenever no act is lacking, intention alone causes a vessel to be susceptible to uncleanness, If a given article is in a physical state in which it can be used, it is susceptible to impurity as soon as a person decides to use it, even if its manufacturing has not been fully completed. Let's take a table for instance. If it was usable and the owner decided to not polish it and use it immediately, the table is susceptible.

But whenever an act is lacking, intention alone does not render it susceptible to uncleanness, except for a fur cover. But if the article cannot be used, then merely intending to use it does not render it susceptible to impurity. The exception to this rule is a fur cover, put over a saddle. This fur cover is susceptible as soon as a person decides to use it, even though he has not yet fully cut it into its proper shape. The reason for its "early" susceptibility is that it is not unusual for people to use unshaped pieces of fur to cover the saddle.