It was narrated that Ibn Mas’ood (may Allah be pleased with him) said:
Between the first heaven and the one above it is (a distance of) five hundred years. Between each of the heavens is (a distance of) five hundred years.
Between the seventh heaven and the Kursiy is (a distance of) five hundred years. Between the Kursiy and the water is (a distance of) five hundred years,
and the Throne is above the water.
Allaah is above the Throne, and nothing whatsoever of your deeds is hidden from Him.
(narrated by Ibn Khuzaymah in al-Tawheed, p. 105; by al-Bayhaqi in al-Asmaa’ wa’l-Sifaat, p. 401). This report was classed as saheeh by Ibn al-Qayyim in Ijtimaa’ al-Juyoosh al-Islamiyah, p. 100; by al-Dhahabi in al-‘Uluw, p. 64).
Shaykh Ibn ‘Uthaymeen said:
This hadeeth stops at Ibn Mas’ood (it is mawqoof), but this is one of the matters concerning which there is no room for personal opinion, so it comes under the heading of marfoo’ [ahaadeeth whose isnaad goes back to the Prophet (peace and blessings of Allaah be upon him)], because Ibn Mas’ood is not known to have taken anything from the Israa’eeliyyaat [reports derived from Jewish sources].
(al-Qawl al-Mufeed Sharh Kitaab al-Tawheed, 3/379)
Imaam Muhammad ibn ‘Abd al-Wahhaab said, in the list of points noted from this hadeeth:
…..(9) The great size of the Kursiy in relation to the heavens.
(10) The great size of the Throne in relation to the Kursiy.
(11) That the Throne is something other than the Kursiy and the water.
(Sharh Kitaab al-Tawheed, p. 667, 668).
Source: www.islamqa.info