Is Ibn al-Qayyim's statement, "If a servant were to truly rely on God in removing a mountain from its place, and were commanded to remove it, he would remove it," sound? And is it true that Ali (may God be pleased with him) alone carried the gate of Khaybar?

There is no problem with the aforementioned statement, and it is consistent with the noble verse: "Allah does not burden a soul beyond its capacity." The story of Ali ibn Abi Talib carrying the gate of Khaybar was mentioned by some scholars, but many verifiers, such as Ibn Taymiyyah and Al-Sakhawi, rejected it, and all its narrations are weak.