The Family of Imran
ٱلَّذِينَ قَالَ لَهُمُ ٱلنَّاسُ إِنَّ ٱلنَّاسَ قَدْ جَمَعُوا۟ لَكُمْ فَٱخْشَوْهُمْ فَزَادَهُمْ إِيمَـٰنًا وَقَالُوا۟ حَسْبُنَا ٱللَّهُ وَنِعْمَ ٱلْوَكِيلُ
Those to whom hypocrites said, "Indeed, the people have gathered against you, so fear them." But it [merely] increased them in faith, and they said, "Sufficient for us is Allah, and [He is] the best Disposer of affairs."
Nearby ayahs help place verse 3:173 in sequence and meaning.
۞ يَسْتَبْشِرُونَ بِنِعْمَةٍ مِّنَ ٱللَّهِ وَفَضْلٍ وَأَنَّ ٱللَّهَ لَا يُضِيعُ أَجْرَ ٱلْمُؤْمِنِينَ
They receive good tidings of favor from Allah and bounty and [of the fact] that Allah does not allow the reward of believers to be lost -
ٱلَّذِينَ ٱسْتَجَابُوا۟ لِلَّهِ وَٱلرَّسُولِ مِنۢ بَعْدِ مَآ أَصَابَهُمُ ٱلْقَرْحُ ۚ لِلَّذِينَ أَحْسَنُوا۟ مِنْهُمْ وَٱتَّقَوْا۟ أَجْرٌ عَظِيمٌ
Those [believers] who responded to Allah and the Messenger after injury had struck them. For those who did good among them and feared Allah is a great reward -
فَٱنقَلَبُوا۟ بِنِعْمَةٍ مِّنَ ٱللَّهِ وَفَضْلٍ لَّمْ يَمْسَسْهُمْ سُوٓءٌ وَٱتَّبَعُوا۟ رِضْوَٰنَ ٱللَّهِ ۗ وَٱللَّهُ ذُو فَضْلٍ عَظِيمٍ
So they returned with favor from Allah and bounty, no harm having touched them. And they pursued the pleasure of Allah, and Allah is the possessor of great bounty.
إِنَّمَا ذَٰلِكُمُ ٱلشَّيْطَـٰنُ يُخَوِّفُ أَوْلِيَآءَهُۥ فَلَا تَخَافُوهُمْ وَخَافُونِ إِن كُنتُم مُّؤْمِنِينَ
That is only Satan who frightens [you] of his supporters. So fear them not, but fear Me, if you are [indeed] believers.