حَسْبُنَا اللَّهُ وَنِعْمَ الْوَكِيلُ
HasbunAllahu wa ni'mal-Wakil
Allah is sufficient for us, and He is the best Disposer of affairs.
This was said by Prophet Ibrahim (AS) when he was thrown into the fire by his people, and by the Companions at the Battle of Uhud when they were told "a great army has gathered against you, so fear them." Instead of panicking, they said these words — and Allah turned the threat into safety and increased them in faith.
Related Du'as
يَا حَيُّ يَا قَيُّومُ بِرَحْمَتِكَ أَسْتَغِيثُ أَصْلِحْ لِي شَأْنِي كُلَّهُ وَلَا تَكِلْنِي إِلَىٰ نَفْسِي طَرْفَةَ عَيْنٍ
O Ever-Living, O Sustainer, by Your mercy I seek help. Set right all my affairs for me, and do not leave me to myself even for the blink of an eye.
Hasanاللَّهُمَّ لَا تَجْعَلْ مُصِيبَتَنَا فِي دِينِنَا وَلَا تَجْعَلِ الدُّنْيَا أَكْبَرَ هَمِّنَا وَلَا مَبْلَغَ عِلْمِنَا
O Allah, do not make our calamity in our religion, and do not make this world our greatest concern or the extent of our knowledge.
Hasanإِنَّا لِلَّهِ وَإِنَّا إِلَيْهِ رَاجِعُونَ
Indeed, to Allah we belong and to Him we shall return.
Sahihوَأُفَوِّضُ أَمْرِي إِلَى اللَّهِ إِنَّ اللَّهَ بَصِيرٌ بِالْعِبَادِ
And I entrust my affair to Allah. Indeed, Allah is Seeing of His servants.
Sahih