Authentic Supplication Number 255.

The Messenger of Allah  said: “Whoever enters the marketplace and says: La ‘ilaha ‘illa ‘allahu wahdahu la shareeka lahu, lahul mulku, wa lahul hamdu, yuhyee wa yumeetu, wa huwa hayyun la yamootu, biyadihil khayru, wa huwa ‘ala kulli shay’in qadeerun (259).

Allah would write for him one thousand thousand merits, would remit from him one thousand thousand sins,and would raise for him [his status] one thousand thousand levels”.

Footnotes.
(259) There is no ‘ilah except Allah, no partner does He have; his is the Kingdom, and to Him is all Praise; He livens, and mortifies; and He is alive; never to die. In his Hand is all good, and He is well able to do everything.

Reporters.
Reported by At-Tirmithi. Al-Albani said that At-Tirmithi weakened it by saying that it was a “strange” hadeeth. A strange hadeeth is one that is reported by only one person at some of its links; however he said it becomes comely when all of its channels are considered. Specifically he referred to Al-Hakim’s (528-539/1),Ibn As-Sunni’s (#178), and Imam Ahmad’s Az-zuhd (#214). He also said that Al-Munthiree said it was comely in At-Targheeb. Albani included this hadeeth in The Authentic of Good Sayings as #183.