Sahih al-Bukhari 4940

Arabic

حَدَّثَنَا سَعِيدُ بْنُ النَّضْرِ، أَخْبَرَنَا هُشَيْمٌ، أَخْبَرَنَا أَبُو بِشْرٍ، جَعْفَرُ بْنُ إِيَاسٍ عَنْ مُجَاهِدٍ، قَالَ قَالَ ابْنُ عَبَّاسٍ ‏{‏لَتَرْكَبُنَّ طَبَقًا عَنْ طَبَقٍ‏}‏ حَالاً بَعْدَ حَالٍ، قَالَ هَذَا نَبِيُّكُمْ صلى الله عليه وسلم‏.‏

English translation

Narrated Ibn `Abbas:(as regards the Verse):--'You shall surely travel from stage to stage (in this life and in the Hereafter).' (It means) from one state to another. That concerns your Prophet

Reference: Sahih al-Bukhari 4940, Book of Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)). English translation by Dr. Muhammad Muhsin Khan.