"I heard the Messenger of Allah ﷺ say: 'The best of remembrance is La ilaha illallah (None has the right to be worshipped but Allah), and the best of supplication is Al-Hamdu Lillah (praise is to Allah).'" (Using translation from Ibn Mājah 3800)

سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ «أَفْضَلُ الذِّكْرِ لَا إِلَهَ إِلَّا اللَّهُ وَأَفْضَلُ الدُّعَاءِ الْحَمْدُ لِلَّهِ»