Hadith 135

Narrated Abu Hurairah (RA): The Prophet (ﷺ) said: "He who prays a Rak'a of the Fajr prayer before the sun rises, has offered the dawn prayer in its time, and he who prays a Rak'a of the 'Asr prayer before the sun sets has offered the afternoon prayer." [Agreed upon]. Muslim reported the same above Hadith in another version narrated by 'Aishah (RA), who narrated 'Sajdah (prostration)' instead of 'Rak'a (prayer unit)' and then he (Muslim) said: "A Sajdah implies a Rak'a."