Narrated ['Abdullah] bin Mas'ud:
"When the Messenger of Allah (ﷺ) reached Sidrat Al-Muntaha" He said: 'There terminates everything that ascends from the earth, and everything that descends from above. So there Allah gave him three, which He did not give to any Prophet before him: He made fiver prayers obligatory upon him, He gave him the last Verses of Surat Al-Baqarah, and He pardoned the grave sins for those of his Ummah who do not associate anything with Allah.' Ibn Mas'ud said regarding the Ayah: "When that covered the Sidrah which did cover it! (53:16)" he said: "The sixth Sidrah in heavens." Sufyan said: "Golden butterflies" and Sufyan indicated with his hand in a fluttering motion. Others besides Malik bin Mighwal said: "There terminates the creatures' knowledge, there is no knowledge for them of what is above that."
English reference: Vol. 5, Book 44, Hadith 3276
Arabic reference: Book 47, Hadith 3587