On the night of his Ascension, fifty prayers were enjoined upon the Prophet ﷺ. Then they were reduced until they were made five. Then a voice called out, "Muhammad, the word with Me is not changed, and you shall have for these five the reward of fifty."
حدثنا محمد بن يحيى النيسابوري حدثنا عبد الرزاق أخبرنا معمر عن الزهري
فرضت على النبي ﷺ ليلة أسري به الصلوات خمسين ثم نقصت حتى جعلت خمسا ثم نودي يا محمد إنه لا يبدل القول لدي وإن لك بهذه الخمس خمسين
[Sahih]. Ahmad narrated it, 3/161, from Abdul-Razzaq with the same chain. Bukhari, no. 349, and Muslim, no. 163, narrated it from the hadith of Zuhri with the same chain, in a longer form.On this subject there are also narrations from Ubada bin Samit [Abu Dawud, no. 425, 1420], Talha bin Ubaydullah [Bukhari, no. 46, and Muslim, no. 11], Abu Dharr [Bukhari, no. 349, and Muslim, no. 163], Abu Qatada [Ibn Majah, no. 1403], Malik bin Sasaa [Bukhari, no. 3207, and Muslim, no. 164], and Abu Saeed Khudri [Abdul-Razzaq, 1/452–453, no. 1769, though the chain contains Abu Harun Abdi].