Another interpretation: "And in all that I have said to you, take heed" (Exodus 23:13) comes to bring in the resting of vessels [the prohibition against letting one's tools and implements do work on the festival, not only one's own labor].
Resting Your Tools and Not Only Yourself on the Festival
Yalkut Shimoni on Torah 355:3
דָּבָר אַחֵר, וּבְכֹל אֲשֶׁר אָמַרְתִּי אֲלֵיכֶם תִּשָּׁמֵרוּ, לְהָבִיא שְׁבִיתַת כֵּלִים.