It is narrated from Sayyiduna Husayn bin Ali (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "If any Muslim man or woman is struck by a calamity, however long ago it may have occurred, and then, on remembering it, says the words of istirja', 'Inna lillahi wa inna ilayhi raji'un' (We belong to Allah and to Him we return), Allah Almighty records for him at that time the very same reward that He promised him on the day the calamity first struck him."
Hadith Referenceمسند أبي يعلى الموصلي / مسند الحسين بن علي بن أبي طالب / 6777
Hadith Takhrij«قال سعيد بن محمد السناري: تالف» «أخرجه مسند أحمد برقم: 1736، وأخرجه المعجم الأوسط للطبراني برقم: 2789، مسند ابویعلیٰ ترقیم الاثری: 6744»