Allah (SwT) has said,

“Whatever in the heavens and on earth declares the glory of Allah, the King, the Holy” (Qur’an, 62:1).

Al-Qudoos means: the One Whose characteristics cannot be conceived by the senses, nor can He be conceived by imagination, nor can He be realized by any mind or reason or judged by any intellect. Linguistically, it is derived from quds, purity or cleanness. “Al-bayt al-muqaddas” means the Purified House, the one in which people purify themselves from the filth of sins.

Paradise is also called the place of quds because it is free from the ills of the life of this world. Arch-angel Gabriel is called in Islam al-ruh al-quds, the Holy Spirit, because he is free from any fault in delivering divine inspiration to the Messengers of Allah (S). Allah (SwT) has described Himself as:

“... the King, the Holy” (Qur’an, 59:23).

And He has also said,

“Whatever in the heavens and on earth declares the glory of Allah, the King, the Holy” (Qur’an, 62:1).

Al-Quddus is the One Who is above need and Whose Attributes are above being deficient. He is the One Who purifies the souls against sinning, Who takes the wicked by their forelocks, Who is above being limited to space or time.

The Messenger of Allah (S) once sent one of his companions to teach Islam to a group of new converts and to lead them in congregational prayers. That companion used not to recite any chapter of the Holy Qur’an (besides, of course, the Fatiha) other than Surah at-Tawhid (or al-Ikhlas, i.e. Ch. 112), so those believers went back once to the Prophet and told him about it.

The Prophet said to them, “Go back and ask him why he does so. “On asking him, the companion answered them by saying, “... because it contains the Attribute of al-Rahman, and this is why I love to recite it so often!” When they told the Prophet this answer, he said to them, “Go back and tell him that the Praised and Glorified One loves him, too”.

Ibn ‘Abbas‎ spent a night once with his cousin the Messenger of Allah (S). When the Messenger of Allah (S) woke up and stood up on his bed, he raised his head towards the heavens and thrice repeated the following statement: Subhana al-Malik al-Quddus! (Glory to the King, the Holy!) Then he recited the last verses of Surah Ali-’Imran starting with the verse:

“Surely in the creation of the heavens and the earth...” (Qur’an, 3:190).