What is the story of the People of the Cloak and who are they? And was Jibreel among them?

The Companions of the Cloak are the Prophet (peace be upon him), Ali, Fatimah, Al-Hasan, and Al-Husayn (may Allah be pleased with them). Gabriel (peace be upon him) is not among them. The verse was revealed in the house of Umm Salamah (may Allah be pleased with her), and the Prophet (peace be upon him) supplicated for them under the cloak, asking Allah to remove all impurity from them and to purify them thoroughly.