Sura Āl-ʿImrān 3:139

وَلَا تَهِنُوا۟ وَلَا تَحْزَنُوا۟ وَأَنتُمُ ٱلْأَعْلَوْنَ إِن كُنتُم مُّؤْمِنِينَ

wa-lā tahinū wa-lā taḥzanū wa-antumu l-aʿlawna in kuntum muʾminīna

So lose not heart, nor fall into despair: For ye must gain mastery if ye are true in Faith.

Sura Āl-ʿImrān 3:146

وَكَأَيِّن مِّن نَّبِىٍّ قَٰتَلَ مَعَهُۥ رِبِّيُّونَ كَثِيرٌ فَمَا وَهَنُوا۟ لِمَآ أَصَابَهُمْ فِى سَبِيلِ ٱللَّـهِ وَمَا ضَعُفُوا۟ وَمَا ٱسْتَكَانُوا۟ وَٱللَّـهُ يُحِبُّ ٱلصَّٰبِرِينَ

wakaayyin min nabiyyin qātala maʿahu ribbīyūna kathīrun fa-mā wahanū limā aṣābahum fī sabīli allāhi wa-mā ḍaʿufū wa-mā astakānū wallāhu yuḥibbu l-ṣābirīna

How many of the prophets fought (in Allah's way), and with them (fought) Large bands of godly men? but they never lost heart if they met with disaster in Allah's way, nor did they weaken (in will) nor give in. And Allah Loves those who are firm and steadfast.

Sura al-Nisāʾ 4:104

وَلَا تَهِنُوا۟ فِى ٱبْتِغَآءِ ٱلْقَوْمِ إِن تَكُونُوا۟ تَأْلَمُونَ فَإِنَّهُمْ يَأْلَمُونَ كَمَا تَأْلَمُونَ وَتَرْجُونَ مِنَ ٱللَّـهِ مَا لَا يَرْجُونَ وَكَانَ ٱللَّـهُ عَلِيمًا حَكِيمًا

wa-lā tahinū fī btighāi l-qawmi in takūnū talamūna fainnahum yalamūna ka-mā talamūna wa-tarjūna mina allāhi mā lā yarjūna wa-kāna allāhu ʿalīman ḥakīman

And slacken not in following up the enemy: If ye are suffering hardships, they are suffering similar hardships; but ye have Hope from Allah, while they have none. And Allah is full of knowledge and wisdom.

Sura Maryam 19:4

قَالَ رَبِّ إِنِّى وَهَنَ ٱلْعَظْمُ مِنِّى وَٱشْتَعَلَ ٱلرَّأْسُ شَيْبًا وَلَمْ أَكُنۢ بِدُعَآئِكَ رَبِّ شَقِيًّا

qalā rabbi innī wahana l-ʿaẓmu minnī wa-ishtaʿala l-rasu shayban wa-lam akun biduʿāika rabbi shaqiyyan

Praying: "O my Lord! infirm indeed are my bones, and the hair of my head doth glisten with grey: but never am I unblest, O my Lord, in my prayer to Thee!

Sura Muḥammad 47:35

فَلَا تَهِنُوا۟ وَتَدْعُوٓا۟ إِلَى ٱلسَّلْمِ وَأَنتُمُ ٱلْأَعْلَوْنَ وَٱللَّـهُ مَعَكُمْ وَلَن يَتِرَكُمْ أَعْمَٰلَكُمْ

fa-lā tahinū wa-tadʿū ilā l-salmi wa-antumu l-aʿlawna wallāhu maʿakum wa-lan yatirakum aʿmālakum

Be not weary and faint-hearted, crying for peace, when ye should be uppermost: for Allah is with you, and will never put you in loss for your (good) deeds.