Al-Quddoos — The Absolutely Pure, The All-Perfect. He is the One who is the absolutely pure in essence and attributes. Al-Quddoos is free from and far above any imperfection, error, facult and shortcoming. He is High Above what does not befit Him.
يُسَبِّحُ لِلَّهِ مَا فِي السَّمَاوَاتِ وَمَا فِي الْأَرْضِ الْمَلِكِ الْقُدُّوسِ الْعَزِيزِ الْحَكِيمِ – 62:1
Whatever is in the heavens and whatever is on the earth is exalting Allah, the Sovereign, the Pure (Al-Quddus), the Exalted in Might, the Wise.
“Al-Quddus is the One who is free from every attribute which a sense might perceive, or imagination may conceive, or to which imagination may instinctively turn or by which the conscience may be moved, or which thinking demands. I do not say: free from defects and imperfections, for the mere mention of that borders on insult… I will rather say, the Holy (al-Quddus) is the one who transcends every one of the attributes of perfection which the majority of creatures think of as perfection.”