In his work on the laws of *shabas* called *Kalkalas Shabas* (at [the beginning of the 3rd chapter](http://www.hebrewbooks.org/pdfpager.aspx?req=40155&st=&pgnum=22&hilite=)), the [author of *Tif'eres Yisra'el*](http://he.wikipedia.org/wiki/%D7%99%D7%A9%D7%A8%D7%90%D7%9C_%D7%9C%D7%99%D7%A4%D7%A9%D7%99%D7%A5) introduces the topic of *muktzeh* by saying that the reason the sages prohibited use of non-essential objects on *shabas* was

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> כדי שיהא שביתת האדם ניכרת שהיא כמצות התורה למען ינוח, שיהא לבו פנוי לתורת ה' ביום שבת.
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> so that a person's cessation would be recognizable as the Biblical commandment "so that one shall rest", such that his mind could be available for God's Tora on *shabas* day.
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From the way he phrases the next few lines, his contention seems to be not just that this is *a* reason for the prohibition against moving *muktzeh* objects, but the *primary* reason therefor.

As opposed to the opinions of Ramba"m and Ra'ava"d, quoted further in the paragraph, which hold that *muktzeh* laws were instituted to prevent forbidden activities being done with the objects in question, the *Tif'eres Yisra'el* appears to believe they were meant to simply free up a person from quotidian busywork, which would detract from his learning/spirituality (or to *represent* such a freeing up).

Is there an earlier source for this explanation of the laws of *muktzeh* - stated as a primary reason or otherwise? It seems pretty extreme and is unsourced, unlike the other explanations he includes.