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.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī

Ribat (guarding and vigilance for the sake of Allah) is better than fasting for a month

ذِكْرُ الْبَيَانِ بِأَنَّ اللَّهَ جَلَّ وَعَلَا يُعْطِي بِتَفَضُّلِهِ الْمُرَابِطَ يَوْمًا أَوْ لَيْلَةً خَيْرًا مِنْ صِيَامِ شَهْرٍ وَقِيَامِهِ

ibnhibban:4623 – Ibn Qutaybah > Yazīd b. Mawhab > al-Layth b. Saʿd > Ayyūb b. Mūsá > Makḥūl > Shuraḥbīl b. al-Simṭ

Salman passed by ˹Shurahbil˺ while he was stationed for guarding and asked, "What are you doing here, Shurahabil?" Shurahabil replied, "I am performing ribat (guarding) in the cause of Allah." Salman said, "I heard the Messenger of Allah ﷺ say, 'The act of guarding for a day or a night is better than fasting and praying for an entire month.'"  

ابن حبّان:٤٦٢٣ – أَخْبَرَنَا ابْنُ قُتَيْبَةَ حَدَّثَنَا يَزِيدُ بْنُ مَوْهَبٍ حَدَّثَنِي اللَّيْثُ بْنُ سَعْدٍ عَنْ أَيُّوبَ بْنِ مُوسَى عَنْ مَكْحُولٍ عَنْ شُرَحْبِيلَ بْنِ السِّمْطِ

أَنَّهُ مَرَّ عَلَيْهِ سَلْمَانُ وَهُوَ مُرَابِطٌ فَقَالَ مَا تَصْنَعُ هَاهُنَا يَا شُرَحْبِيلُ؟ فَقَالَ شُرَحْبِيلُ أُرَابِطُ فِي سَبِيلِ اللَّهِ قَالَ سَلْمَانُ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ «رِبَاطُ يَوْمٍ أَوْ لَيْلَةٍ خَيْرٌ مِنْ صِيَامِ شَهْرٍ وَقِيَامِهِ»  

See similar narrations below:

Collected by Aḥmad, Suyūṭī
ahmad:6653 – Ḥasan > Ibn Lahīʿah > Yazīd b. Abū Ḥabīb > Sūwayd b. Qays > ʿAbdullāh b. ʿAmr

[Machine] The Messenger of Allah ﷺ said: "The action of guarding a frontier for one day is better than fasting for a whole month and performing night prayers (qiyam)."  

أحمد:٦٦٥٣ – حَدَّثَنَا حَسَنٌ حَدَّثَنَا ابْنُ لَهِيعَةَ حَدَّثَنَا يَزِيدُ بْنُ أَبِي حَبِيبٍ عَنْ سُوَيْدِ بْنِ قَيْسٍ عَنْ عَبْدِ اللهِ بْنِ عَمْرٍو

أَنَّ رَسُولَ اللهِ ﷺ قَالَ رِبَاطُ يَوْمٍ خَيْرٌ مِنْ صِيَامِ شَهْرٍ وَقِيَامِهِ