Allah will extend the last worldly day until the Mahdī arrives
from the Prophet ﷺ who said: "A man is coming from the people of my family whose name agrees with my name."
ʿāsim said: Abū Ṣālih narrated to us from Abū Hurayrah who said: "If there did not remain in the world but one day, then Allah would extend that day until he comes."
عَنِ النَّبِيِّ ﷺ قَالَ: «يَلِي رَجُلٌ مِنْ أَهْلِ بَيْتِي يُوَاطِئُ اسْمُهُ اسْمِي۔» قَالَ عَاصِمٌ وَأَخْبَرَنَا أَبُو صَالِحٍ عَنْ أَبِي هُرَيْرَةَ قَالَ: «لَوْ لَمْ يَبْقَ مِنَ الدُّنْيَا إِلاَّ يَوْمٌ لَطَوَّلَ اللَّهُ ذَلِكَ الْيَوْمَ حَتَّى يَلِيَ۔»