Not graded
Hisn al-Muslim (Fortress of the Muslim) 264
((إِنَّ أَفْضَلَ الدُّعَاءِ الْحَمْدُ لِلَّهِ، وَأَفْضَلَ الذِّكْرِ لاَ إِلَهَ إِلاَّ اللَّهُ)).
(Jabir Ibn ‘AAabdullah related that the Messenger of Allah said: ‘Verily, the best supplication is: (All praise is for Allah.) and indeed, the best form of remembrance is: (None has the right to be worshipped except Allah.))
Cited in Hisn al-Muslim (Fortress of the Muslim) (No. 264).