Prohibition of heresies in religion

Imam Al-Nawawi’s Riyad-us-Saliheen
Chapter 18
Prohibition of heresies in religion

Allah, the Exalted, says:

“So after the truth, what else can there be, save error?”. (10:32)

“We have neglected nothing in the Book”. (6:38)

“(And) if you differ in anything amongst yourselves, refer it to Allah and His Messenger (sallallaahu ’alayhi wa sallam)”. (4:59)

“And verily, this is My straight path, so follow it, and follow not (other) paths, for they will separate you away from His path”. (6:153)

“Say (O Muhammad (sallallaahu ’alayhi wa sallam) to mankind): ‘If you (really) love Allah then follow me (i.e., accept Islamic Monotheism, follow the Qur’an and the Sunnah), Allah will love you and forgive you your sins”. (3:31)

169. `Aishah (May Allah be pleased with her) reported: Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “If anyone introduces in our matter something which does not belong to it, will be rejected”.
[Al-Bukhari and Muslim].

The narration in Muslim says: “If anybody introduces a practice which is not authenticated by me, it is to be rejected”.

170.  Jabir (May Allah be pleased with him) reported: Whenever the Messenger of Allah (sallallaahu ’alayhi wa sallam) delivered a Khutbah, his eyes would become red, his tone loud and he showed anger as if he were warning us against an army. He (sallallaahu ’alayhi wa sallam) would say, “The enemy is about to attack you in the morning and the enemy is advancing against you in the evening”. He would further say, “I am sent with the final Hour like these two fingers of mine.” Messenger of Allah (sallallaahu ’alayhi wa sallam) held up his index finger and the middle finger together to illustrate. He used to add: “To proceed, the best speech is the Book of Allah and the best guidance is the guidance of Muhammad (sallallaahu ’alayhi wa sallam), the worst practice is the introduction of new practices in Islam and every Bid`ah is a misguidance”. He would also say, “I am, in respect of rights, nearer to every believer than his own self. He who leaves an estate, it belongs to his heirs, and he who leaves a debt, it is my responsibility to pay it off.’‘ [Muslim].

Same Hadith as reported by `Irbad bin Sariyah (May Allah be pleased with him) has already been recorded in the previous chapter regarding safeguarding the Sunnah of the Prophet (sallallaahu ’alayhi wa sallam).
(See Hadith number 158)