Ṣaḥīḥ al-Bukhārī
صَحِيحُ البُخَارِي
Considered to be the most authentic after the Qurʾān. Full name: al-Jāmiʿ al-Musnad al-Ṣaḥīḥ al-Mukhtaṣar min Umūr Rasūlallāh ﷺ wa-Sunnatihī wa-Ayyāmihī (الجامع المسند الصحيح المختصر من أمور رسول الله ﷺ وأيامه) (The Comprehensive Summarized Authentic Chains from the Affairs of the Messenger of Allah ﷺ, his Sunnah, and his Life and Times). Sources: sunnah.com for the Arabic text and English translation. The English translation has been improved by myself and other contributors.
Random ḥadīth in Bukhārī
A man heard another man reciting (Surat-Al-Ikhlas) 'Say He is Allah, (the) One.' (112. 1) repeatedly. The next morning he came to Messenger of Allah ﷺ and informed him about it as if he thought that it was not enough to recite. On that Messenger of Allah ﷺ said, "By Him in Whose Hand my life is, this Surah is equal to one-third of the Qur'an!"
سَمِعَ رَجُلاً يَقْرَأُ {قُلْ هُوَ اللَّهُ أَحَدٌ} يُرَدِّدُهَا فَلَمَّا أَصْبَحَ جَاءَ إِلَى رَسُولِ اللَّهِ ﷺ فَذَكَرَ ذَلِكَ لَهُ وَكَأَنَّ الرَّجُلَ يَتَقَالُّهَا فَقَالَ رَسُولُ اللَّهِ ﷺ وَالَّذِي نَفْسِي بِيَدِهِ إِنَّهَا لَتَعْدِلُ ثُلُثَ الْقُرْآنِ