In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Allaah [The Most High] said:
إِذۡ جَعَلَ ٱلَّذِينَ كَفَرُواْ فِى قُلُوبِهِمُ ٱلۡحَمِيَّةَ حَمِيَّةَ ٱلۡجَـٰهِلِيَّةِ فَأَنزَلَ ٱللَّهُ سَڪِينَتَهُ ۥ عَلَىٰ رَسُولِهِۦ وَعَلَى ٱلۡمُؤۡمِنِينَ وَأَلۡزَمَهُمۡ ڪَلِمَةَ ٱلتَّقۡوَىٰ وَكَانُوٓاْ أَحَقَّ بِہَا وَأَهۡلَهَاۚ وَكَانَ ٱللَّهُ بِكُلِّ شَىۡءٍ عَلِيمً۬ا
When those who disbelieve had put in their hearts pride and haughtiness- the pride and haughtiness of the time of ignorance, then Allah sent down His Sakinah (calmness and tranquillity) upon His Messenger and upon the believers, and made them stick to the word of piety [i.e. none has the right to be worshipped but Allaah], and they were well entitled to it and worthy of it. And Allaah is the All-Knower of everything. [Surah Al-Fath 26]
[إِذۡ جَعَلَ ٱلَّذِينَ كَفَرُواْ فِى قُلُوبِهِمُ ٱلۡحَمِيَّةَ حَمِيَّةَ ٱلۡجَـٰهِلِيَّةِ – When those who disbelieve had put in their hearts pride and haughtiness the pride and haughtiness of the time of ignorance]:
This was when the polytheists refused to allow [the scribe of the Messenger (sallal-laahu-alayhi-wasallam)] to write the statement [بِسۡمِ ٱللهِ ٱلرَّحۡمَـٰنِ ٱلرَّحِيمِ] whilst an agreement was been made between them and the Messenger. They also refused to allow the Messenger [sallal-laahu-alayhi-wasallam] and the believers to visit the kabah in that year lest the people say that the Muslims entered Makkah by overcoming the Quraish. [Ref 1] This affair [i.e. this pride and haughtiness of theirs] is from the [manners] of the people of the Pre-Islamic era of ignorance. It was something that did not cease be present in their hearts until it led them to commit many acts of disobedience [to Allaah].
Then Allaah said: [فَأَنزَلَ ٱللَّهُ سَڪِينَتَهُ ۥ عَلَىٰ رَسُولِهِۦ وَعَلَى ٱلۡمُؤۡمِنِينَ – then Allah sent down His Sakinah (calmness and tranquillity) upon His Messenger and upon the believers]:
Anger did not lead them to deal with the polytheists in the manner the polytheists dealt with them, rather they exercised patience, whilst adhering to Allaah’s judgement. They adhered to the conditions that obligated on them to refrain from violating what Allaah [The Most High] prohibited them from violating, regardless of the speech and blame of the blamers.
Then Allaah [The Most High] said: [وَأَلۡزَمَهُمۡ ڪَلِمَةَ ٱلتَّقۡوَىٰ – And made them stick to the word of piety (i.e. none has the right to be worshipped but Allah]: Meaning: Allaah made them adhere to Laa ilaaha illal laah and the obligations attached to it. Allaah [The Most High] made them adhere to it and fulfil its obligations, so they adhered to it and fulfilled it. [وَكَانُوٓاْ أَحَقَّ بِہَا وَأَهۡلَهَاۚ – and they were well entitled to it and worthy of it]: Meaning: They were entitled to it more than others and were from those worthy of it, because Allaah knows the good [i.e. Eemaan, obedience to Allaah and His Messenger etc] that was in their hearts, and this is why Allaah said: [وَكَانَ ٱللَّهُ بِكُلِّ شَىۡءٍ عَلِيمً۬ا – And Allah is the All-Knower of everything].
[Source: (Tayseer al-Kareem Ar-Rahmaan Fee Tafseer Kalaam Al-Mannaan). slightly paraphrased]
[Ref 1: Read the long narration in Saheeh Al-Bukhaari regarding this incident. Hadeeth Number 2731 Vol 3. Book of Conditions]