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
ibnmajah:3793 – Abū Bakr > Zayd b. al-Ḥubāb > Muʿāwiyah b. Ṣāliḥ > ʿAmr b. Qays al-Kindī > ʿAbdullāh b. Busr > Aʿrābī

"The laws of Islam are burdensome for me. Tell me of something that I will be able to adhere to. He said: 'Always keep your tongue moist with the remembrance of Allah, the Mighty and Sublime.'"  

ابن ماجة:٣٧٩٣ – حَدَّثَنَا أَبُو بَكْرٍ حَدَّثَنَا زَيْدُ بْنُ الْحُبَابِ أَخْبَرَنِي مُعَاوِيَةُ بْنُ صَالِحٍ أَخْبَرَنِي عَمْرُو بْنُ قَيْسٍ الْكِنْدِيُّ عَنْ عَبْدِ اللَّهِ بْنِ بُسْرٍ أَنَّ أَعْرَابِيًّا قَالَ

لِرَسُولِ اللَّهِ ﷺ إِنَّ شَرَائِعَ الإِسْلاَمِ قَدْ كَثُرَتْ عَلَىَّ فَأَنْبِئْنِي مِنْهَا بِشَىْءٍ أَتَشَبَّثُ بِهِ قَالَ لاَ يَزَالُ لِسَانُكَ رَطْبًا مِنْ ذِكْرِ اللَّهِ ﷻ  

See similar narrations below:

Collected by Tirmidhī, Ḥākim
tirmidhi:3375 – Abū Kurayb > Zayd b. Ḥubāb > Muʿāwiyah b. Ṣāliḥ > ʿAmr b. Qays > ʿAbdullāh b. Busr > a man

A man said: “O Messenger of Allah ﷺ, indeed, the legislated acts of Islam have become too much for me, so inform me of a thing that I should stick to.” He ﷺ said: “Let not your tongue cease to be moist with the remembrance of Allah.”  

Abū ʿĪsá said that this Ḥadīth is Ḥasan-Gharīb in this particular context.
الترمذي:٣٣٧٥ – حَدَّثَنَا أَبُو كُرَيْبٍ حَدَّثَنَا زَيْدُ بْنُ حُبَابٍ عَنْ مُعَاوِيَةَ بْنِ صَالِحٍ عَنْ عَمْرِو بْنِ قَيْسٍ عَنْ عَبْدِ اللَّهِ بْنِ بُسْرٍ ؓ أَنَّ رَجُلاً قَالَ

يَا رَسُولَ اللَّهِ إِنَّ شَرَائِعَ الإِسْلاَمِ قَدْ كَثُرَتْ عَلَىَّ فَأَخْبِرْنِي بِشَيْءٍ أَتَشَبَّثُ بِهِ قَالَ لاَ يَزَالُ لِسَانُكَ رَطْبًا مِنْ ذِكْرِ اللَّهِ  

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ مِنْ هَذَا الْوَجْهِ
hakim:1822 – Abū al-Faḍl al-Ḥasan b. Yaʿqūb al-ʿAdl > Yaḥyá b. Abū Ṭālib > Zayd b. al-Ḥubāb > Muʿāwiyah b. Ṣāliḥ > ʿAmr b. Qays al-Sakūnī > ʿAbdullāh b. Busr > Aʿrābī

"The laws of Islam are burdensome for me. Tell me of something that I will be able to adhere to. He said: 'Always keep your tongue moist with the remembrance of Allah, the Mighty and Sublime.'" (Using translation from Ibn Mājah 3793)  

الحاكم:١٨٢٢ – حَدَّثَنَا أَبُو الْفَضْلِ الْحَسَنُ بْنُ يَعْقُوبَ الْعَدْلُ ثنا يَحْيَى بْنُ أَبِي طَالِبٍ ثنا زَيْدُ بْنُ الْحُبَابِ ثنا مُعَاوِيَةُ بْنُ صَالِحٍ حَدَّثَنِي عَمْرُو بْنُ قَيْسٍ السَّكُونِيُّ عَنْ عَبْدِ اللَّهِ بْنِ بُسْرٍ أَنَّ أَعْرَابِيًّا قَالَ

لِرَسُولِ اللَّهِ ﷺ إِنَّ شَرَائِعَ الْإِسْلَامِ قَدْ كَثُرَتْ عَلَيَّ فَأَنْبِئْنِي بِشَيْءٍ أَتَشَبَّثُ بِهِ فَقَالَ «لَا يَزَالُ لِسَانُكَ رَطْبًا مِنْ ذِكْرِ اللَّهِ»  

هَذَا حَدِيثٌ صَحِيحُ الْإِسْنَادِ وَلَمْ يُخَرِّجَاهُ