Surah Ali 'Imran 3:139

وَلَا تَهِنُوا۟ وَلَا تَحْزَنُوا۟ وَأَنتُمُ ٱلْأَعْلَوْنَ إِن كُنتُم مُّؤْمِنِينَ

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

Translation: Saheeh International

Tafsir

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.

Excerpt from Tafsir al-Jalalayn, commentary on 3:139, via Quran.com. The reader has the full commentary and 9 more tafsirs.