The Prophet ﷺ said, "There are two qualities, or two practices, which no Muslim servant maintains regularly without entering Paradise. They are easy, yet few are those who act upon them. One should say 'SubhanAllah' ten times after every prayer, 'Alhamdulillah' ten times, and 'Allahu Akbar' ten times. That is one hundred and fifty on the tongue, and one thousand five hundred on the scale. And when one takes to bed, he should say 'Allahu Akbar' thirty-four times, 'Alhamdulillah' thirty-three times, and 'SubhanAllah' thirty-three times. That is one hundred on the tongue, and one thousand on the scale."I saw the Messenger of Allah ﷺ counting them on his hand.They asked, "Messenger of Allah, how are they easy yet few act upon them?"He replied, "Shaytan comes to one of you in his sleep and puts him to sleep before he can say them, and he comes to him during his prayer and reminds him of some need before he can say them."
عن النبي ﷺ قال: خصلتان أو خلتان لا يحافظ عليهما عبد مسلم إلا دخل الجنة، هما يسير، ومن يعمل بهما قليل، يسبح في دبر كل صلاة عشرا، ويحمد عشرا، ويكبر عشرا، فذلك خمسون ومائة باللسان، وألف وخمسمائة في الميزان، ويكبر أربعا وثلاثين إذا أخذ مضجعه، ويحمد ثلاثا وثلاثين، ويسبح ثلاثا وثلاثين، فذلك مائة باللسان، وألف فى الميزان، فلقد رأيت رسول الله ﷺ يعقدها بيده، قالوا: يا رسول الله كيف هما يسير ومن يعمل بهما قليل؟ قال: يأتى أحدكم- يعنى الشيطان- في منامه فينومه قبل أن يقوله، ويأتيه في صلاته فيذكره حاجة قبل أن يقولها.
Abu Dawud (5065) narrated it via the route of Shubah, Tirmidhi (3410) via the route of Ismail bin Ulaya, Nasai (1348) via the route of Hammad, and Ibn Majah (926) via the routes of Ismail, Muhammad bin Fudayl, Abu Yahya Taymi, and Ibn Ajlah, all of them narrating from Ata bin Saaib, from his father, from Abdullah bin Amr, who mentioned it. The wording given here is that of Abu Dawud.Tirmidhi said, "Hasan sahih. Shubah and Thawri narrated this hadith from Ata bin Saaib, and Amash narrated this hadith from Ata bin Saaib in an abridged form."Its isnad is sahih. Ata bin Saaib is trustworthy, and the leading scholars affirmed his trustworthiness, except that he became confused in his memory toward the end of his life. However, the narrations of Shubah, Thawri, and Hammad from him predate that confusion.His statement, "That makes one hundred and fifty," means over the course of five times each day and night. And "dubur" means right after the prayer.