"When Allah, the exalted, speaks to send revelation, the inhabitants of heaven hear the clanging of a bell from the heavens like a chain being dragged across a rock, and they swoon. They continue to remain like that until Jibril comes to them. When he comes to them, they recover and say: 'O Jibril, what did your Lord say?' He would say: 'The truth,' and they would say: 'The truth, the truth.'"
Sunan Abi Dawud Book 42, Hadith 143