Mukhtasar Bukhari

It is narrated from Sayyiduna Abu Ayyub Ansari and Ibn Mas'ud (may Allah be pleased with them) that the Prophet Muhammad (peace and blessings be upon him) said: "Whoever recites the above-mentioned phrase (the declaration of faith: La ilaha illallah...) ten times, will receive a reward as if he has freed one slave from the descendants of Isma'il (peace be upon him)."

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) said: "Whoever recites in a day one hundred times: (La ilaha illallah wahdahu la sharika lahu, lahu’l-mulku wa lahu’l-hamdu wa huwa ‘ala kulli shay’in qadeer) — There is no deity worthy of worship except Allah, He is alone, He has no partner, His is the dominion and His is all praise, and He is powerful over everything — he will have the reward of freeing ten slaves, and one hundred good deeds will be written in his record, and one hundred sins will be erased, and he will be safe from Satan that day until evening, and no one will be better than him except the one who recites it more than this."