Sunan an-Nasa'i, Volume 3, Book 24, Hadith 2878 (DarusSalam) ⓘ

It was narrated that Ibn Abbas said: "The Messenger of Allah said on the day of the conquest of Makkah: 'Allah, the Might and Sublime, has made this land sacred, and it was not permissible to fight therein for anyone before me. It was permitted for me for a few hours of a day, and it is sacred by the decree of Allah, the Might and Sublime."

أَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ، قَالَ حَدَّثَنَا يَحْيَى بْنُ آدَمَ، قَالَ حَدَّثَنَا مُفَضَّلٌ، عَنْ مَنْصُورٍ، عَنْ مُجَاهِدٍ، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَوْمَ فَتْحِ مَكَّةَ ‏ "‏ إِنَّ هَذَا الْبَلَدَ حَرَامٌ حَرَّمَهُ اللَّهُ عَزَّ وَجَلَّ لَمْ يَحِلَّ فِيهِ الْقِتَالُ لأَحَدٍ قَبْلِي وَأُحِلَّ لِي سَاعَةً مِنْ نَهَارٍ فَهُوَ حَرَامٌ بِحُرْمَةِ اللَّهِ عَزَّ وَجَلَّ ‏" ‏ ‏.‏