I heard the Messenger of Allah ﷺ say, "Whoever declares, 'There is no god but Allah,' and rejects everything worshipped besides Allah, his wealth and blood become inviolable, and his reckoning rests with Allah."
سمعت رسول الله ﷺ يقول: من قال: لا إله إلا الله، وكفر بما يعبد من دون الله، حرم ماله ودمه، وحسابه على الله.
Muslim narrated it in "Faith" (23) through several routes from Marwan Fazari, from Abu Malik, from his father, and he related the hadith. Abu Malik is Saad bin Tariq Ashjai, and his father is Tariq bin Ashyam bin Masud Ashjai.