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
suyuti:158a –

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

السيوطي:١٥٨a –

("ابكُوا، وإن لَمْ تبكُوا فَتَبَاكَوْا".  

[هـ] ابن ماجة عن سعد بن أبي وقاص

See similar narrations below:

Collected by Ibn Mājah, Aḥmad's Zuhd
ibnmajah:4196 – ʿAbdullāh 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:٤١٩٦ – حَدَّثَنَا 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  

ahmad-zuhd:559 – ʿAbdullāh > Bī > Wakīʿ > Misʿar from my father

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

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

قَالَ أَبُو بَكْرٍ ؓ «ابْكُوا فَإِنْ لَمْ تَبْكُوا فَتَبَاكَوْا»