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.
ibnmajah:4196ʿAbdullāh b. Aḥmad b. Bashīr b. Dhakwān al-Dimashqī > al-Walīd b. Muslim > Abū Rāfiʿ > Ibn Abū Mulaykah > ʿAbd al-Raḥman b. al-Sāʾib > Saʿd b. Abū Waqqāṣ

‘Weep, and if you cannot weep then pretend to weep.”  

ابن ماجة:٤١٩٦حَدَّثَنَا عَبْدُ اللَّهِ بْنُ أَحْمَدَ بْنِ بَشِيرِ بْنِ ذَكْوَانَ الدِّمَشْقِيُّ حَدَّثَنَا الْوَلِيدُ بْنُ مُسْلِمٍ حَدَّثَنَا أَبُو رَافِعٍ عَنِ ابْنِ أَبِي مُلَيْكَةَ عَنْ عَبْدِ الرَّحْمَنِ بْنِ السَّائِبِ عَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ ابْكُوا فَإِنْ لَمْ تَبْكُوا فَتَبَاكَوْا  


See similar narrations below:

Collected by Aḥmad's Zuhd, Suyūṭī
ahmad-zuhd:559ʿAbdullāh > Bī > Wakīʿ > Misʿar from my father

‘Weep, and if you cannot weep then pretend to weep.” (Using translation from Ibn Mājah 4196)   

الزهد لأحمد:٥٥٩حَدَّثَنَا عَبْدُ اللَّهِ حَدَّثَنِي أبِي حَدَّثَنَا وَكِيعٌ حَدَّثَنَا مِسْعَرٌ عَنْ أَبِي عَوْنٍ الثَّقَفِيِّ عَنْ عَرْفَجَةَ السُّلَمِيِّ قَالَ

قَالَ أَبُو بَكْرٍ ؓ «ابْكُوا فَإِنْ لَمْ تَبْكُوا فَتَبَاكَوْا»