(Imām Bukhārī narrates): Hassan al-Wasiti narrated the hadith to us, he said: Al-Mufaddal bin Fadalah narrated the hadith to us, from Uqail, from Ibn Shihab, from Hazrat Anas bin Malik (Allāh be pleased with him), he narrates that
when the Prophet ﷺ departed before the decline of the sun, he ﷺ would delay the Zuhr prayer until the time of Asr, then combine the two of them, and when the sun declined, he ﷺ would offer the Zuhr prayer, then mount.
Reference: Sahih Al Bukhari 1111