Tafsir of Az-Zukhruf 43:41

{فَإِمَّا نَذْهَبَنَّ بِكَ}

The "ma" (in imma) is equivalent to the lam of an oath, in that when it enters, the emphatic nun (nūn al-ta’kīd) accompanies it.

The meaning is: If We take you (in death) before We grant you victory over them and heal the hearts of the believers by punishing them, {فَإِنَّا مِنْهُم مُّنتَقِمُونَ}—a most severe retribution in the Hereafter. This is like His saying: "Or We take you (in death), then to Us they will be returned" (Ghafir: 77).

And if We will to fulfill the punishment We promised them during your lifetime—which is the day of Badr—they are under Our dominion and power; they cannot escape Us. He described them as having intense stubbornness in disbelief and misguidance, then followed it with a severe threat of punishment in this world and the Hereafter.

It is recited as nurinnaka (with the light nun).

{فَاسْتَمْسِكْ بِالَّذِي أُوحِيَ إِلَيْكَ}

It is recited as bi-alladhi ūḥiya (passive voice), referring to Allah, the Almighty and Exalted.

The meaning is: Whether We hasten victory and triumph for you, or delay it until the Day of Resurrection, hold fast to what We have revealed to you and act upon it. For it is the Straight Path, from which none deviates except one who is astray and wretched. Increase in firmness every day in defending the religion of Allah. Do not let impatience with their affairs lead you to any softness or laxity in your mission. Rather, act as one who is steadfast—neither hastened by the acceleration of victory, nor discouraged by its delay.

{وَإِنَّهُ لَذِكْرٌ لَّكَ وَلِقَوْمِكَ وَسَوْفَ تُسْأَلُونَ * وَاسْأَلْ مَنْ أَرْسَلْنَا مِن قَبْلِكَ مِن رُّسُلِنَا أَجَعَلْنَا مِن دُونِ الرَّحْمَنِ آلِهَةً يُعْبَدُونَ}