Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
hakim:2381al-Ḥasan b. Ḥalīm al-Marwazī > Abū al-Muwajjih > ʿAbdān > ʿAbdullāh > Muḥammad b. Maʿn al-Ghifārī Abū Maʿn > Zuhrah b. Maʿbad al-Qurashī > Abū Ṣāliḥ a freed slave of ʿUthmān

[Machine] "Narrated that he heard the Messenger of Allah ﷺ say: 'A day in the way of Allah is better than a thousand days in what is other than it, so let everyone look to himself.'"  

الحاكم:٢٣٨١أَخْبَرَنِي الْحَسَنُ بْنُ حَلِيمٍ الْمَرْوَزِيُّ ثنا أَبُو الْمُوَجِّهِ أَنْبَأَ عَبْدَانُ أَنْبَأَ عَبْدُ اللَّهِ أَنْبَأَ مُحَمَّدُ بْنُ مَعْنٍ الْغِفَارِيُّ أَبُو مَعْنٍ ثنا زُهْرَةُ بْنُ مَعْبَدٍ الْقُرَشِيُّ عَنْ أَبِي صَالِحٍ مَوْلَى عُثْمَانَ قَالَ سَمِعْتُ عُثْمَانَ بْنَ عَفَّانَ فِي مَسْجِدِ الْخَيْفِ بِمِنًى

وَحَدَّثَنَا أَنَّهُ سَمِعَ رَسُولَ اللَّهِ ﷺ يَقُولُ «يَوْمٌ فِي سَبِيلِ اللَّهِ خَيْرٌ مِنْ أَلْفِ يَوْمٍ فِيمَا سِوَاهُ فَلْيَنْظُرْ كُلُّ امْرِئٍ لِنَفْسِهِ»  

هَذَا حَدِيثٌ صَحِيحٌ عَلَى شَرْطِ الْبُخَارِيِّ وَلَمْ يُخَرِّجَاهُ على شرط البخاري

See similar narrations below:

Collected by Nasāʾī
nasai:3170ʿAmr b. ʿAlī > ʿAbd al-Raḥman b. Mahdī > Ibn al-Mubārak > Abū Maʿn > Zahrah b. Maʿbad > Abū Ṣāliḥ a freed slave of ʿUthmān > ʿUthmān b. ʿAffān ؓ

"uthman bin 'Affan said: 'I heard the Messenger of Allah ﷺ say: A day in the cause of Allah is better than a thousand days doing anything else.'"  

النسائي:٣١٧٠أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ قَالَ حَدَّثَنَا ابْنُ الْمُبَارَكِ قَالَ حَدَّثَنَا أَبُو مَعْنٍ قَالَ حَدَّثَنَا زَهْرَةُ بْنُ مَعْبَدِ عَنْ أَبِي صَالِحٍ مَوْلَى عُثْمَانَ قَالَ قَالَ عُثْمَانُ بْنُ عَفَّانَ ؓ

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ يَوْمٌ فِي سَبِيلِ اللَّهِ خَيْرٌ مِنْ أَلْفِ يَوْمٍ فِيمَا سِوَاهُ