Abu Sa'id Al-Khudri (May Allah be pleased with him) said:
The Prophet (ﷺ) said, "The dwellers of Jannah will look at those in the upper abodes above them as you look at a shining star which remains in the eastern or western horizon; such will be the difference in superiority which some of them have over others." The Messenger of Allah (ﷺ) was asked: "Will those be the dwellings of the Prophets which no one else will be able to reach?" He (ﷺ) replied, "Yes, but by Him in Whose Hand my soul is! men who believed in Allah and acknowledged the truthfulness of the Messengers will reach them."[Al-Bukhari and Muslim].
App reference: Book 20, Hadith 19
Arabic/English book reference: Book 20, Hadith 1887