It has been narrated on the authority of Anas b. Malik who said: When they (Companions of the Holy Prophet) were overwhelmed with grief and distress on his return from Hudaibiya where he had slaughtered his sacrificial beasts (not being allowed to proceed to Mecca), the Qur'anic verse: Inna fatahna... laka fathan mobinan to fauzan 'aziman, was revealed to him. (At this) he said: On me has descended a verse that is dearer to me than the whole world.
Source: sunnah.com
Other translations
Arabic
وَحَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ الْجَهْضَمِيُّ، حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، حَدَّثَنَا سَعِيدُ بْنُ أَبِي، عَرُوبَةَ عَنْ قَتَادَةَ، أَنَّ أَنَسَ بْنَ مَالِكٍ، حَدَّثَهُمْ قَالَ لَمَّا نَزَلَتْ { إِنَّا فَتَحْنَا لَكَ فَتْحًا مُبِينًا * لِيَغْفِرَ لَكَ اللَّهُ} إِلَى قَوْلِهِ { فَوْزًا عَظِيمًا} مَرْجِعَهُ مِنَ الْحُدَيْبِيَةِ وَهُمْ يُخَالِطُهُمُ الْحُزْنُ وَالْكَآبَةُ وَقَدْ نَحَرَ الْهَدْىَ بِالْحُدَيْبِيَةِ فَقَالَ " لَقَدْ أُنْزِلَتْ عَلَىَّ آيَةٌ هِيَ أَحَبُّ إِلَىَّ مِنَ الدُّنْيَا جَمِيعًا " .
sunnah.com