What is meant by "وثن" (idol) in Ibn al-Qayyim's verse: "Until it is said about the idol, which... they claim has no imperfection"?

Ibn al-Qayyim's verses addressed the Oneness of Worship (Tawheed al-Ibadah), clarifying the obligation of dedicating all worship exclusively to Allah, without associating any partners with Him, whether in prayer, supplication (du'a), vows (nadhr), pilgrimage (Hajj), or reliance (tawakkul). Ibn al-Qayyim warned against the delusion of some who claim to be Muslims, yet have taken the graves of their shaykhs as objects of worship, directing supplications and vows to them, believing that these figures will intercede for them with Allah. This action, he pointed out, resembles the practices of the polytheists (mushrikin). The Quranic verses affirm that those who take protectors other than Allah claim that these protectors bring them closer to Allah. However, Allah the Almighty has refuted this claim. Ibn Kathir clarified that the polytheists used to worship idols in order to draw closer to Allah, and this is the same misconception that polytheists have relied upon throughout the ages. For those who worship them, graves are akin to the idols that were worshipped; anything worshipped besides Allah is an idol. The Prophet, peace and blessings be upon him, warned against taking his grave as an idol and cursed those who took the graves of their prophets as places of worship (masajid). Thus, the grave worshippers equated the occupants of the shrines with Allah in love and seeking closeness, to the extent that their love for them surpassed their love for Allah.