Musar על מועד קטן 49:20

It was also forbidden to sit on a bed which a Torah scroll lies upon (Moed Katan 25a). Likewise, they said: "it is forbidden to throw out holy writings, even Halachot (laws) and Agadot" (Eruvin 98a, Rambam Hilchot Sefer Torah ch.10). Likewise, they forbade putting books of the Prophets and Writings on top of the Five Books of Moses (Megilah 27a). These are things that our sages, of blessed memory, forbade on the entire congregation of Israel. But the Chasid should learn from them and add on them in various ways for the honor of the Name of the L-rd, his G-d.