What does the illustration of the mustard grain teach us about Kingdom increase?
مَاذَا يُعَلِّمُنَا مَثَلُ حَبَّةِ ٱلْخَرْدَلِ عَنِ ٱلنُّمُوِّ ٱلنَّاتِجِ عَنِ ٱلْمُنَادَاةِ بِرِسَالَةِ ٱلْمَلَكُوتِ ؟‏