Hadith: I see what you do not see. Heaven is groaning and it has a right to be groaning: there is no space the width of four fingers in it but an angel placing his forehead in prostration to Allah, the Exalted

عن أبي ذر رضي الله عنه مرفوعاً: «إني أرى ما لا ترون، أطَّتِ السماء وحُقَّ لها أن تَئِطَ، ما فيها موضع أربع أصابع إلا ومَلَكٌ واضع جبهته ساجدا لله تعالى، والله لو تعلمون ما أعلم، لضحكتم قليلا ولبكيتم كثيرا، وما تلذذتم بالنساء على الفُرُشِ، ولخرجتم إلى الصُّعُداتِ تَجْأَرُون إلى الله تعالى».
[حسن] - [رواه الترمذي وابن ماجه وأحمد]

Abu Dharr (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: “I see what you do not see. Heaven is groaning and it has a right to be groaning: there is no space the width of four fingers in it but an angel placing his forehead in prostration to Allah the Exalted.”
[Hasan/Sound by virtue of corroborating evidence] - [Narrated by Ibn Majah - Narrated by At-Termedhy - Narrated by Ahmad]

Explanation

The Messenger of Allah (may Allah's peace and blessings be upon him) said: I know and see things that you do not know and see. There was a groaning sound in the heaven like the sound of a camel when the load is placed on its back, and the heaven had every right to groan. The reason for the groaning is that there is not a space of four fingers except that there is an angel prostrating his forehead before Allah, the Exalted. By Allah! If you knew what I know about Allah's magnificent majesty and the severity of His vengeance, you would laugh little and weep much from fear of Allah's absolute power and domination. You would not enjoy women in beds out of terror (of His anger and punishments), and you would go out to the open spaces and roads, crying out loud and imploring Allah, the Exalted, for help and mercy.