Verily Allah would make a wind to blow from the side of the Yemen more delicate than silk and would spare none but cause him to die who, in the words of Abu 'Alqama, has faith equal to the weight of a grain; while Abdul-'Aziz said: having faith equal to the weight of a dust particle.  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ يَبْعَثُ رِيحًا مِنَ الْيَمَنِ أَلْيَنَ مِنَ الْحَرِيرِ فَلاَ تَدَعُ أَحَدًا فِي قَلْبِهِ قَالَ أَبُو عَلْقَمَةَ مِثْقَالُ حَبَّةٍ وَقَالَ عَبْدُ الْعَزِيزِ مِثْقَالُ ذَرَّةٍ مِنْ إِيمَانٍ إِلاَّ قَبَضَتْهُ