Al Quddoos(The holy) , As salam(The peace)
The one who is far greater and far removed from any imperfection, or that he resemble any of his creation. Hence he is far removed from any defect just as he is far removed from anything resembling him or coming close to resembling him in any of his attributes of perfection.
“There is nothing like him.” (42:11)
“There is no one equal to or comparable to him”(112:3)
“Do you know of any who is similar to him?”(19:65)
“Then do not set up rivals to Allah”(2:22)
Al-Quddoos is similar in meaning to as-Salam in that they both negate any form of imperfection, while at the same time include unlimited perfection in any way. This is due to the fact that when deficiency is removed, then all that remains is perfection.
“Whatsoever is in the heavens and the earth glorifies Allah – the King, the Holy, the-Almighty, the All- Wise.”(62:1)
Source : islamhouse