That she borrowed a necklace from Asma' and then it got lost. So Messenger of Allah ﷺ sent some people from his companions in search of it. In the meantime the stated time for the prayer became due and they offered their prayer without ablution. When they came to the Prophet, they complained about it to him, so the Verse regarding Tayammum was revealed . Usaid bin Hudair said, "(O ʿAisha!) may Allah bless you with a good reward, for by Allah, never did a difficulty happen in connection with you, but Allah made an escape from it for you, and brought Allah's Blessings for the Muslims."  

أَنَّهَا اسْتَعَارَتْ مِنْ أَسْمَاءَ قِلاَدَةً فَهَلَكَتْ فَأَرْسَلَ رَسُولُ اللَّهِ ﷺ نَاسًا مِنْ أَصْحَابِهِ فِي طَلَبِهَا فَأَدْرَكَتْهُمُ الصَّلاَةُ فَصَلَّوْا بِغَيْرِ وُضُوءٍ فَلَمَّا أَتَوُا النَّبِيَّ ﷺ شَكَوْا ذَلِكَ إِلَيْهِ فَنَزَلَتْ آيَةُ التَّيَمُّمِ فَقَالَ أُسَيْدُ بْنُ حُضَيْرٍ جَزَاكِ اللَّهُ خَيْرًا فَوَاللَّهِ مَا نَزَلَ بِكِ أَمْرٌ قَطُّ إِلاَّ جَعَلَ لَكِ مِنْهُ مَخْرَجًا وَجُعِلَ لِلْمُسْلِمِينَ فِيهِ بَرَكَةٌ