((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.))
At-Tirmidhi 5/462, Ibn Majah 2/1249, and Al-Hakim who graded it authentic and Ath-Tbahabi agreed 1/503. See Al-Albani, Sahihul-Jami' As-Saghir 1/362.