It wasnarrated from Abu Ayyub that the Prophet (ﷺ) used to performfourRak'ah before the Zuhr when the sun had passed its zenith, and hedid not separate them with a Taslim. He said, "The gates of heavenareopened when the sun passes its zenith." (ID)
English reference (ID): Vol. 1, Book 5, Hadith 1157 (ID)
Arabic reference (ID): Book 5, Hadith 1212 (ID)