أتاني جِبْريلُ فأخْبَرَنِي أنَّ أمَّتِي سَتَقْتُلُ ابْنِي هذا – يَعْني الحُسَيْنَ – وأتانِي بِتُرْبَةٍ مِنْ تءَرْبَت
(ك) عن أم الفضل بنت الحارث.)
Gabriel came to me and told me that members of my ummah would kill this son of mine – meaning al-Husayn – and he came bringing with him a red clay  . ” This hadeeth was narrated by al-Hakim 3/176 from the words of Umm al-Fadl bint al-Haris.
Sheikh al-Albani called the hadith authentic. See “Sahih al-jami ‘as-sagir” 61, “al-Silsil as-sahiha” 821.
 Husayn ibn ‘Ali ibn Abu Talib is the grandson of the Prophet Muhammad, peace and blessings be upon him.
 Apparently, this refers to the clay, which turned red with blood, as an indication that al-Husayn will be killed. Allah knows better.