Dhikr

وعن سعد بن أبي وقاص رضي الله عنه قال‏:‏ جاء أعرابي إلى رسول الله صلى الله عليه وسلم فقال‏:‏ علمني كلامًا أقوله‏.‏ قال‏:‏

‏”‏قل لا إله إلا الله وحده لا شريك له، الله أكبر كبيرا والحمد لله كثيرا وسبحان الله رب العالمين، ولا حول ولا قوة إلا بالله العزيز الحكيم” قال فهؤلاء لربي، فما لي‏؟‏ قال‏:‏ ‏”‏قل اللهم اغفر لي، وارحمني، واهدني، وارزقني‏”‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏

Sa’d bin Abu Waqqas (May Allah be pleased with him) reported:
A bedouin came to the Messenger of Allah (ﷺ) and said to him, “Teach me a few words to recite frequently.” He (ﷺ) said, “Say:
“La ilaha illallahu wahdahu la sharika lahu; Allahu Akbar kabiran, wal-hamdu lillahi kathiran, wa subhan-Allahi Rabbil-‘alamin; wa la hawla wa la quwwata illa billahil-‘Azizil-Hakim.”
(there is no true god except Allah the One and He has no partner with Him; Allah is the Greatest and greatness is for Him. All praise is due to Him. Allah, the Rubb of the worlds is free from imperfection; there is no might and power but that of Allah, the All-Powerful and the All-Wise.)”‘ The bedouin said: “All of these for my Rubb. But what is for me?” Thereupon he (Messenger of Allah (ﷺ)) said, “You should say: ‘Allahummaghfir li, warhamni, wahdini, warzuqni (O Allah! Grant me pardon, have mercy upon me, direct me to righteousness and provide me subsistence)’.”

[Muslim].