Mishkat al-Masabih 27 Fitan كتاب الفتن 13

وَعَنْ مَعْقِلِ بْنِ يَسَارٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ «الْعِبَادَةُ فِي الْهَرْجِ كَهِجْرَةٍ إِلَيَّ» . رَوَاهُ مُسلم

Ma’qil b. Yasar reported God’s messenger as saying, “The reward for engaging in worship during the turmoil will be like that for coming to me as emigrants.” Muslim transmitted it.