the Messenger of Allah ﷺ said: “The best remembrance is: ‘there is none worthy of worship except Allah (Lā ilāha illallāh)’ and the best supplication is: ‘All praise is due to Allah (Al-ḥamdulillāh).’”
سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ أَفْضَلُ الذِّكْرِ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَفْضَلُ الدُّعَاءِ الْحَمْدُ لِلَّهِ