Narrated 'Abdullah bin 'Umar:
"I heard 'Umar bin Al-Khattab saying: 'The Messenger of Allah (ﷺ) said: "Four before Zuhr, after the zenith, are reckoned with their like from Salat As-Sahr (meaning the reward is like that of the two Sunan and obligatory Rak'ah of Fajr)." The Messenger of Allah (ﷺ) said: "There is nothing but that it glorifies Allah at that hour." Then he recited the Ayah: Their shadows shift from right to left, prostrating to Allah while they are humble (16:48). (ES)
English reference (ES): Vol. 5, Book 44, Hadith 3128 (ES)
Arabic reference (ES): Book 47, Hadith 3420 (ES)