What is the meaning of "and tranquility descended upon them..."?

Question:
Regarding the tranquility (in the hadith )?

Answer:
As mentioned previously: it is a great created entity that descends, accompanied by angels who hear the remembrance. Some scholars said that it is a type of angel, and the apparent meaning of the texts is that it is a type like a cloud in which there are angels who listen to the remembrance and listen to the recitation. This is like what Usayd ibn Hudayr (may Allah be pleased with him) saw when he was praying at night and that tranquility descended, containing things like lamps, so the Prophet (peace and blessings be upon him) informed him that it had descended for the recitation of the Qur'an.
Q: What are its signs on people, scholars, and students of knowledge?
The Shaykh: There are no signs, there are no signs on the student of knowledge. However, there is exhortation to be sincere and to pay attention to the remembrance of Allah and the recitation of the Qur'an out of desire and out of sincerity for Allah (Exalted and Majestic is He). This is among the causes of the angels descending, and among the causes of the servant benefiting from his deed and its multiplication for him if he is sincere to Allah and truthful in his work.
Q: Some of them defined it by saying: it is a state in which the heart finds peace and settles, ceasing to incline toward desires?
The Shaykh: No, it is not this tranquility. The tranquility descends from the sky in the air between the sky and the earth.
Q: In a wording of the hadith, the Prophet (peace and blessings be upon him) said: ?
The Shaykh: It means: in the tranquility, it descends in the cloud to listen to the Qur'an.