His saying: "By the 'Asr (the afternoon/time)," meaning: the 'Asr of the day; it is the time between the sun's meridian (zawal) and the night, and it is an oath.
قَوْله: ﴿وَالْعصر﴾ يَعْنِي: عَصْرَ النَّهَارِ؛ وَهُوَ مَا بَيْنَ زَوَالِ الشَّمْسِ إِلَى اللَّيْلِ وَهُوَ قسم