The Prophet ﷺ said, "The best of speech is, 'Glory be to Allah, all praise is due to Allah, there is no god but Allah, and Allah is the greatest.'"
قال حدثنا وكيع قال حدثنا الأعمش عن أبي صالح
عن النبي ﷺ قال أفضل الكلام سبحان الله والحمد لله ولا إله إلا الله والله أكبر
Its isnad is sahih. Something similar is found in Bukhari 8/173, printing of Shab, in the Book of Iman, when he said, "By Allah, I will not speak," and in Ibn Majah, in the Book of Adab, 2/1253, no. 3811, from Samura bin Jundab.