‘What did you use to say about this before Islam?’
They replied, ‘We used to say, “A great man has been born,” or, “A great man has died.”’
He said, ‘It is not hurled for anyone’s birth or death. Rather, when our Lord—blessed and exalted is He—decrees a matter, the bearers of the Throne glorify Him, then the angels of the heaven beneath them glorify Him, and that glorification is relayed until it reaches the inhabitants of the lowest heaven. Those closest to the bearers of the Throne then ask them, “What has your Lord said?” They answer, “The truth; and He is the Most High, the Most Great.” The same words are repeated, and the denizens of the heavens inform one another until the news reaches the lowest heaven. The jinn then snatch at the hearing and pass it to their confederates, who pass it to theirs, whereupon they are struck by the shooting-stars. Whatever they transmit exactly as it was heard is true, but they taint it and add to it.’

Likewise, in the other well-known ḥadīth transmitted by Nuʿaym ibn Ḥammād from al-Walīd ibn Muslim, from ʿAbd al-Raḥmān ibn Yazīd, from ʿAbd Allāh ibn Abī Zakariyā, from Rajāʾ ibn Ḥaywah, from al-Nawwās ibn Samʿān, he said:
The Messenger of Allah ﷺ said, ‘When Allah wills to reveal a command, He speaks with the revelation; when He speaks, the heavens are seized by a violent trembling—or, he said, a severe quaking—out of awe of Allah. When the inhabitants of the heavens hear it, they fall senseless and prostrate to Allah. The first to raise his head is Gabriel, and Allah speaks to him from the revelation with whatever He wishes. Gabriel then proceeds with it, and whenever he passes a heaven its angels ask, “What has our Lord said, O Gabriel?” He replies, “He has said the truth; and He is the Most High, the Most Great.” All of them repeat exactly what Gabriel has said, and Gabriel carries the revelation on to wherever Allah has commanded in the heavens or on the earth.’
This narration was recorded by Ibn Abī Ḥātim, al-Ṭabarī, and others.

As for His words, “fuzziʿa ʿan qulūbihim” (“when the terror is lifted from their hearts”), it means that He removes the fear from them, as a number of the early scholars have explained.