Mishkat al-Masabih 4 Prayer كتاب الصلاة 41

وَعَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الْوَقْتُ الْأَوَّلُ مِنَ الصَّلَاةِ رِضْوَانُ اللَّهِ وَالْوَقْتُ الْآخَرُ عَفْوُ اللَّهِ» . رَوَاهُ التِّرْمِذِيّ

Ibn ‘Umar reported God’s Messenger as saying, “The earliest time for prayer is what pleases God, and the latest time is what God allows as a concession.” Tirmidhi transmitted it.