"The Deen is Naseehah."

Bismillah.

Sahih Muslim reports that the Prophet (sallallahu alayhi wasallam) said, “The Deen is naseehah.” The sahabah asked, “To whom?” He (sallallahu alayhi wasallam) replied, “To Allah and His Book, and His Messenger and to the leaders of the Muslims and to the common Muslims.” (Hadith no.7, Nawawi’s Forty Hadith)

What is naseehah?

Lane’s Lexicon (p. 2802) defines naseehah as,

"Sincere, honest, or faithful, advice, or counsel, and conduct ... which is for the good of the person …"

"Naseehah embodies every type of virtue and the desire for all forms of goodness."

"Doing well by others."

It is the most comprehensive word in the Arabic language.

1. Naseehah to Allah means to fulfil your obligations to Him, like salah, zakah, fasting in Ramadan and hajj. The greatest obligation is salah. As well as, believing in tawhid and only saying about Allah what He has said about Himself and what the Prophet (sallallahu alayhi wasallam) said about Him.
2. Naseehah to Allah’s Book means to believe in it, to recite it properly, to apply it into your life and to take lessons from it. It also means to defend it against misinterpretation and to call others to believe in it.
3. Naseehah to Allah’s Messenger (Sallallahu aleyhi wasallam) means to believe in him, to love and respect him, to obey him and to defend his honour. It also means to follow his Sunnah, to honour and love his family, as well as the Sahabah.
4. Naseehah to the leaders of the Muslims which includes the scholars and the political and community leaders of the Muslims. Here naseehah means to give them sincere advice, to be patient with them when they make a mistake and to follow them in their correct decisions. It must be noted that Hikmah is needed to advise leaders of the Muslims, and this must be done in private, not with the intention to expose, embarrass and humiliate the person.
5. Naseehah to the common Muslims means to teach them about Islam, to guide them to the truth, to warn them about the akhirah, to encourage them to enjoin what is virtuous and to forbid what is evil.

Some scholars have also said that from a dawn perspective, naseehah is also for the non-Muslims.

It is for this reason some scholars have stated that this Hadith encompasses the entire Deen of Islam.

The sahabah they implemented this Hadith in their lives and showed us by example what it means to give naseehah.

At-Tabarani reports that the sahabi, Jarir (radi Allahu anhu) told his slave to purchase a horse for him. So the slave went and purchased a horse for 300 dinars from a Muslim seller. When Jarir (radi Allahu anhu) saw the horse, he went back to the seller and offered him 400 dinars, which he accepted. Then he then kept offering more money until he had agreed to pay 800 dinars for the horse. When he was asked about why he did this, he said, “When I became a Muslim, I made an oath to the Prophet (sallallahu alayhi wasallam) to perform salah, to pay zakah and to give naseehah to every Muslim.” 

Source:

Al-Id, I. D. A Treasury of Hadith: A Commentary on Nawawi’s Selection of Forty Prophetic Traditions. Mokrane Guezzou (trans.), pp. 46-49. Kube Publishing.

Zarabozo, J. D. 1999. Commentary on the Forty Hadith of Al-Nawawi, Vol.1, Hadith no.7, pp. 477-499. Al-Basheer Publications & Translations.