The Messenger of Allah ﷺ said, "Whoever denies a single verse of the Quran has made the striking of his neck lawful. And whoever says, 'There is no god but Allah alone, with no partner, and that Muhammad is His servant and messenger,' no one has any way against him, unless he commits an offense for which a prescribed penalty must be carried out."
حدثنا نصر بن علي الجهضمي حدثنا حفص بن عمر حدثنا الحكم بن أبان عن عكرمة
قال رسول الله ﷺ من جحد آية من القرآن فقد حل ضرب عنقه ومن قال لا إله إلا الله وحده لا شريك له وأن محمدا عبده ورسوله فلا سبيل لأحد عليه إلا أن يصيب حدا فيقام عليه
No references are available.
[Its chain of transmission is daif] Ibn Adi narrated it, 2/793, through the hadith of Hafs bin Umar Adani, in abbreviated form.Adani's nickname was al-Farkh, and he is daif, as stated in Taqrib and elsewhere. Busiri graded the hadith daif because of him.