It was narrated that Anas bin Malik said: “If the Messenger of Allah صلی اللہ علیہ وآلہ وسلم was setting out on a journey before the sun passed its zenith, he would delay Zuhr until the time of ‘Asr, then he would stop and combine the prayers. If the sun passed its zenith before he set out, he would pray Zuhr and then set off. (Sahih)