Silsilat al-Ahadith al-Sahihah

Sayyiduna Hakim bin Hizam (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings of Allah be upon him) was sitting among his companions (may Allah be pleased with them), when suddenly he (peace be upon him) began to ask: "Do you hear what I am hearing?" They replied: "We are not hearing anything." He (peace be upon him) said: "I am hearing the creaking of the sky, and it is only fitting that it should creak, for there is not even a space the width of a handspan in it except that there is an angel in prostration or standing (in worship)."