It is narrated from Aisha (may Allah be pleased with her), she says: We were on a journey with the Prophet (ﷺ) when my necklace broke (got lost), so the Messenger of Allah (ﷺ) stayed to look for it, while the people of the caravan had no water with them, so the verse of tayammum was revealed.
Hadith Referenceمسند الإمام الشافعي / كتاب الطهارة / 85
Hadith Takhrijأخرجه البخاري: التيمم، باب (334) ومسلم، الحيض، باب التيمم (367)۔