As for hanging plain, non-figured drapery on the walls: if this is done out of need—such as shielding against heat or cold—there is no harm in it, for it is being used for a genuine benefit, like the curtain over a doorway or the clothing a person wears. If, however, it is done without necessity, it is disliked (makrūh) and provides a valid excuse for declining an invitation—meaning a wedding feast—and for not accepting it. The proof is what Sālim ibn ʿAbd Allāh ibn ʿUmar narrated. He said:
“I was married during the time of Abū Ayyūb. My father announced the wedding, and Abū Ayyūb was among those informed. They had covered my house with a green tent-cloth. Abū Ayyūb hurried over, peered in, and saw the house draped with that green cloth. He said, ‘O ʿAbd Allāh, are you covering the walls?’ My father—embarrassed—replied, ‘The women overruled us, O Abū Ayyūb.’ Abū Ayyūb answered, ‘If there were anyone I feared they might overrule, it was not you.’ Then he said, ‘I will not eat your food, nor will I enter your house,’ and he left.” Al-Athram recorded this report.

It is also related that ʿAbd Allāh ibn Yazīd al-Khatmī was invited to a meal. When he saw that the house had been upholstered, he sat outside and wept. When asked, “What makes you weep?” he replied, “The Messenger of Allah ﷺ once saw a man who had patched his cloak with a piece of leather and said, ‘The world has revealed itself to you’—he said it three times—then added: ‘Are you better today, or will you be when a bowl is brought to you in the morning and another in the evening, when one of you sets out in one suit and returns in another, and when you veil your houses as the Kaʿbah is veiled?’”

ʿAbd Allāh then said, “Should I not weep when I have lived to see you veiling your houses the way the Kaʿbah is veiled?”

Al-Khallāl, with his chain of transmission, reported from Ibn ʿAbbās and ʿAlī ibn al-Ḥusayn that the Prophet ﷺ forbade covering the walls, and ʿĀʾishah reported that the Prophet ﷺ never instructed us, from whatever provisions we had, to cover the walls. End of quotation.

Eighth point: He says, “We even find some of them declaring that for a Muslim to say ‘Our Master Muhammad’ is an innovation and therefore impermissible, and they go to extreme lengths in this.”