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
quran:3:139 –

So do not weaken and do not grieve, and you will be superior if you are ˹true˺ believers.  

Faint not, shrink ˹not˺ from fighting the disbelievers, neither grieve, for what befell you at Uhud, for you shall prevail, through victory over them, if you are, truly, believers. (the response to this ˹last conditional clause˺ is the sum ˹meaning˺ of what has preceded it).
القرآن:٣:١٣٩ –

وَلَا تَهِنُوا وَلَا تَحْزَنُوا وَأَنْتُمُ الْأَعْلَوْنَ إِنْ كُنْتُمْ مُؤْمِنِينَ  

{ولا تهنوا} تضعفوا عن قتال الكفار {ولا تحزنوا} على ما أصابكم بأحد {وأنتم الأعلون} بالغلبة عليهم {إن كنتم مؤمنين} حقا وجوابه دل عليه مجموع ما قبله.