Surah Al-Qasas 28:35

قَالَ سَنَشُدُّ عَضُدَكَ بِأَخِيكَ وَنَجْعَلُ لَكُمَا سُلْطَـٰنًا فَلَا يَصِلُونَ إِلَيْكُمَا ۚ بِـَٔايَـٰتِنَآ أَنتُمَا وَمَنِ ٱتَّبَعَكُمَا ٱلْغَـٰلِبُونَ

[Allāh] said, "We will strengthen your arm through your brother and grant you both supremacy so they will not reach you. [It will be] through Our signs; you and those who follow you will be the predominant."

Translation: Saheeh International

Tafsir

He said ‘We will strengthen your arm We will make you strong by means of your brother and We will give authority victory so that they will not be able to touch either of you with any evil; go both of you with Our signs the two of you and those who follow you two will be the victors’ over them.

Excerpt from Tafsir al-Jalalayn, commentary on 28:35, via Quran.com. The reader has the full commentary and 9 more tafsirs.