إِنَّا لِلَّهِ وَإِنَّا إِلَيْهِ رَاجِعُونَ
Inna lillahi wa inna ilayhi raji'un
Indeed, to Allah we belong and to Him we shall return.
The istirja' — said upon hearing any bad news, any loss, any calamity. The Quran says those who say this when struck by misfortune "are the ones upon whom are blessings from their Lord and mercy. And it is those who are the rightly guided" (2:157). Two facts that reframe every tragedy: you belong to Allah (so He has the right to take what is His), and you are returning to Him (so this separation is temporary).
Related Du'as
اللَّهُمَّ لَا سَهْلَ إِلَّا مَا جَعَلْتَهُ سَهْلًا وَأَنْتَ تَجْعَلُ الْحَزْنَ إِذَا شِئْتَ سَهْلًا
O Allah, nothing is easy except what You make easy, and You can make difficulty easy if You wish.
Sahihيَا 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 اجْعَلْ لِي مِنْ كُلِّ هَمٍّ فَرَجًا وَمِنْ كُلِّ ضِيقٍ مَخْرَجًا وَارْزُقْنِي مِنْ حَيْثُ لَا أَحْتَسِبُ
O Allah, grant me relief from every worry, a way out from every difficulty, and provide for me from where I do not expect.
Hasanاللَّهُمَّ رَحْمَتَكَ أَرْجُو فَلَا تَكِلْنِي إِلَى نَفْسِي طَرْفَةَ عَيْنٍ وَأَصْلِحْ لِي شَأْنِي كُلَّهُ لَا إِلَٰهَ إِلَّا أَنْتَ
O Allah, it is Your mercy that I hope for, so do not leave me to myself even for the blink of an eye, and set right all of my affairs. There is no deity except You.
Hasan