وَإِذَا حُيِّيتُمْ بِتَحِيَّةٍ فَحَيُّوا بِأَحْسَنَ مِنْهَا أَوْ رُدُّوهَا إِنَّ اللَّهَ كَانَ عَلَى كُلِّ شَيْءٍ حَسِيبًا ﴿۸۶﴾ اللَّهُ لَا إِلَهَ إِلَّا هُوَ لَيَجْمَعَنَّكُمْ إِلَى يَوْمِ الْقِيَامَةِ لَا رَيْبَ فِيهِ وَمَنْ أَصْدَقُ مِنَ اللَّهِ حَدِيثًا ﴿۸۷﴾ فَمَا لَكُمْ فِي الْمُنَافِقِينَ فِئَتَيْنِ وَاللَّهُ أَرْكَسَهُمْ بِمَا كَسَبُوا أَتُرِيدُونَ أَنْ تَهْدُوا مَنْ أَضَلَّ اللَّهُ وَمَنْ يُضْلِلِ اللَّهُ فَلَنْ تَجِدَ لَهُ سَبِيلًا ﴿۸۸﴾

﴾86﴿ Wa izaa huyyeetum bitahaiyyatin fahaiyoo bi ahsana minhaaa aw ruddoohaa; innal laaha kaana 'alaa kulli shai'in Haseeba
﴾87﴿ Allaahu laaa ilaaha illaa huwa la yajma'annakum ilaa Yawmil Qiyaamati laa raiba feeh; wa man asdaqu min allaahi hadeesaa
﴾88﴿ Famaa lakum fil munaafiqeena fi'ataini wallaahu arkasahum bimaa kasaboo; A' tureedoona an tahdoo man adallal laahu wa many yudli lillaahu falan tajida lahoo sabeelaa

﴾86﴿ And when you are greeted with a greeting, then respond with one better than it or return it with one equal to it.
Surely, Allah is ever an accountant over all things.
﴾87﴿ Allah is not worthy of worship except Him alone.
He will surely gather you all together on the Day of Resurrection—there is no doubt about it.
And who is more truthful than Allah in speech
﴾88﴿ So what is the matter with you that you have become two groups concerning the hypocrites, while Allah has cast them back (into error) because of what they have earned?
Do you wish to guide those whom Allah has sent astray?
And whoever Allah leads astray—you will never find a way for him.

[86] This means that when someone greets you with salam, respond to it properly.
Likewise, when someone invites you to jihad, respond in the best way.
“Tahiyyah” (greeting) is to say, “Wa ‘alaykum as-salam wa rahmatullahi wa barakatuh,” and “rudduha” (return it) is simply to say, “Wa ‘alaykum as-salam.”
[87] This is the matter of tawhid (the Oneness of Allah).
The purpose is that you should strive in jihad and da‘wah for this cause.
In the first sentence of this verse is the matter of tawhid; in the second, faith in the Day of Judgment; and in the third, the truthfulness of the Noble Qur’an.
[88] In this verse, the different types of hypocrites are mentioned—some of them should be fought against.
Here, it refers to those hypocrites who have not migrated, live in enemy lands (Dar al-Harb), and cooperate with the disbelievers.
Some Muslims said it was not permissible to fight them, while others said they were disbelievers and should be fought—so Allah forbade the Muslims from this disagreement.
Some commentators say this verse was revealed about the hypocrites who turned back from the Battle of Uhud, so the purpose is to prohibit disagreement about their being hypocrites.
“An tahdū” (to guide) here means granting the ability to have faith, or labeling them as rightly guided; it does not simply mean to guide, because that cannot be religiously forbidden.