Sahih al-Bukhari 52:45
Narrated Sa`id bin Jubair:
A Jew from Hira asked me which one of the two periods Musa (i.e. Prophet Moses) completed. I said, "I don't know, (but wait) till I see the most learned 'Arab and inquire him about it." So, I went to Ibn `Abbas and asked him. He replied, "Moses completed the longer and better period." Ibn `Abbas added, "No doubt, an apostle of Allah always does what he says."
Reference
Sahih al-Bukhari 52:45
In-book reference
Book 52, Hadith 45
Arabic Text
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ الرَّحِيمِ، أَخْبَرَنَا سَعِيدُ بْنُ سُلَيْمَانَ، حَدَّثَنَا مَرْوَانُ بْنُ شُجَاعٍ، عَنْ سَالِمٍ الأَفْطَسِ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، قَالَ سَأَلَنِي يَهُودِيٌّ مِنْ أَهْلِ الْحِيرَةِ أَىَّ الأَجَلَيْنِ قَضَى مُوسَى قُلْتُ لاَ أَدْرِي حَتَّى أَقْدَمَ عَلَى حَبْرِ الْعَرَبِ فَأَسْأَلَهُ. فَقَدِمْتُ، فَسَأَلْتُ ابْنَ عَبَّاسٍ فَقَالَ قَضَى أَكْثَرَهُمَا وَأَطْيَبَهُمَا، إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم إِذَا قَالَ فَعَلَ.