Mustadrak al-Hakim — Hadith 3589

It is narrated from Sayyiduna Abbas bin Abd al-Muttalib (may Allah be pleased with him) that we were sitting with the Messenger of Allah (peace and blessings be upon him) at al-Batha when a cloud passed by, and the Messenger of Allah (peace and blessings be upon him) asked: "Do you know what this is?" We said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "This is al-sahab (cloud)." We too said: It is cloud. Then he (peace and blessings be upon him) said: "And this is al-muzn (rain-bearing cloud)." We too said: It is al-muzn. Then he (peace and blessings be upon him) said: "And this is al-'anan (cloud spread across the horizon of the sky)." Then he (peace and blessings be upon him) remained silent for a while, then asked: "Do you know how much distance there is between the heaven and the earth?" We said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "Between the two is a distance of five hundred years' journey, and from each heaven to the next heaven is also a distance of five hundred years' journey, and the thickness of each heaven is five hundred years' journey. Above the seventh heaven is a sea, between whose top and bottom is as much distance as there is between the earth and the heaven. Then above that are eight aw'al (angels in the form of mountain goats), (whose height) is equal to the distance between the earth and the heaven, and Allah Almighty is above all of that, and nothing of the deeds of the children of Adam is hidden from Him."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.