The Virtue of asserting that We all belong to Allah, during Afflictions
There are several Ahadith that mention the rewards of admitting that the return is to Allah by saying:
[إِنَّا لِلَّهِ وَإِنَّـآ إِلَيْهِ رَجِعونَ]
("Truly, to Allah we belong and truly, to Him we shall return.'') when afflictions strike. For instance, Imam Ahmad reported that Umm Salamah narrated: Once, Abu Salamah came back after he was with Allah's Messenger and said: I heard Allah's Messenger recite a statement that made me delighted. He said:
«لَا يُصِيبُ أَحَدًا مِنَ الْمُسْلِمِينَ مُصِيبَةٌ فَيَسْتَرْجِعُ عِنْدَ مُصِيبَتِهِ ثُمَّ يقُولُ: اللَّهُمَّ أْجُرْنِي فِي مُصِيبَتِي وأَخْلِفْ لِي خَيْرًا مِنْهَا، إِلَّا فَعَلَ ذلِكَ بِه»
(No Muslim is struck with an affliction and then says Istirja` when the affliction strikes, and then says: `O Allah! Reward me for my loss and give me what is better than it,' but Allah will do just that.) Umm Salamah said: So I memorized these words. When Abu Salamah died I said Istirja` and said: "O Allah! Compensate me for my loss and give me what is better than it.'' I then thought about it and said, "Who is better than Abu Salamah'' When my `Iddah (the period of time before the widow or divorced woman can remarry) finished, Allah's Messenger asked for permission to see me while I was dyeing a skin that I had. I washed my hands, gave him permission to enter and handed him a pillow, and he sat on it. He then asked me for marriage and when he finished his speech, I said, "O Messenger of Allah! It is not because I do not want you, but I am very jealous and I fear that you might experience some wrong mannerism from me for which Allah would punish me. I am old and have children.'' He said:
«أمَّا مَا ذَكَرْتِ مِنَ الْغَيْرَةِ فَسَوْفَ يُذْهِبُهَا اللهُ عَزَّ وَجَلَّ عَنْكِ، وَأَمَّا مَا ذَكَرْتِ مِنَ السِّنِّ فَقَدْ أَصَابَنِي مِثْلُ الَّذِي أَصَابَكِ، وَأَمَّا مَا ذَكَرْتِ مِنَ الْعِيَالِ فَإِنَّمَا عِيَالُكِ عِيَالِي»
(As for the jealousy that you mentioned, Allah the Exalted will remove it from you. As for your being old as you mentioned, I have suffered what you have suffered. And for your having children, they are my children too.) She said, "I have surrendered to Allah's Messenger.'' Allah's Messenger married her and Umm Salamah said later, "Allah compensated me with who is better than Abu Salamah: Allah's Messenger .'' Muslim reported a shorter version of this Hadith.
[إِنَّ الصَّفَا وَالْمَرْوَةَ مِن شَعَآئِرِ اللَّهِ فَمَنْ حَجَّ الْبَيْتَ أَوِ اعْتَمَرَ فَلاَ جُنَاحَ عَلَيْهِ أَن يَطَّوَّفَ بِهِمَا وَمَن تَطَوَّعَ خَيْرًا فَإِنَّ اللَّهَ شَاكِرٌ عَلِيمٌ ]
(158. Verily, As-Safa and Al-Marwah are of the symbols of Allah. So it is not a sin on him who performs Hajj or `Umrah (pilgrimage) of the House to perform Tawaf between them. And whoever does good voluntarily, then verily, Allah is All-Recognizer, All-Knower).