Part of verse 173 of Surah Ali 'Imran, a declaration of complete reliance on Allah.
It means 'Allah is sufficient for us, and He is the best Disposer of affairs.' The verse records how the believers responded when people tried to frighten them: their faith only grew stronger. It is a well-loved supplication for moments of fear, pressure, or worry.
- 3:173
ٱلَّذِينَ قَالَ لَهُمُ ٱلنَّاسُ إِنَّ ٱلنَّاسَ قَدْ جَمَعُوا۟ لَكُمْ فَٱخْشَوْهُمْ فَزَادَهُمْ إِيمَٰنًۭا وَقَالُوا۟ حَسْبُنَا ٱللَّهُ وَنِعْمَ ٱلْوَكِيلُ
Allazeena qaala lahumun naasu innan naasa qad jama'oo lakum fakhshawhuin fazaadahum eemaannanwa wa qaaloo hasbunal laahu wa ni'malwakeel
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."