The Prophet ﷺ said, "If even as much as a fingernail's worth of what is in Paradise were to appear, it would adorn everything between the horizons of the heavens and the earth. And if a man from the people of Paradise were to look out and his bracelets became visible, they would blot out the light of the sun just as the sun blots out the light of the stars."
حدثنا سويد بن نصر أخبرنا ابن المبارك أخبرنا ابن لهيعة عن يزيد بن أبي حبيب
عن النبي ﷺ قال لو أن ما يقل ظفر مما في الجنة بدا لتزخرفت له ما بين خوافق السموات والأرض ولو أن رجلا من أهل الجنة اطلع فبدا أساوره لطمس ضوء الشمس كما تطمس الشمس ضوء النجوم
ﷺ Reference: [hasan] Ahmad narrated it (1/171) through Ibn Mubarak, by this same chain, and it is found in Zuhd of Ibn Mubarak, no. 416. Ibn Lahia explicitly stated that he heard it directly, in the narration of Hasan bin Musa (Ahmad 1/169), and Layth bin Saad followed him in this (Ilal of Daraqutni 4/335, 336, no. 608). The hadith has supporting narrations which I have mentioned in the takhrij of Nihayah, no. 1346.