Imâm an-Nawawî's 40 Hadîth

"The slave will never be able to attain the ranks of the Muttaqoon (pious ones) until he leaves those things which do not seem to have any harm in them, fearing that they may indeed be harmful/unlawful."

What is naseehah and who is it for?

He who innovates something in this matter of ours [i.e. Islaam] that is not of it will have it rejected [by Allah]”.

Advice to stay upon that which is clear and a warning against indulging in things which are doubtful. "That which is lawful is clear and that which is unlawful is clear, and between the two of them are doubtful matters about which many people do not know. Thus he who avoids doubtful matters clears himself in regard to his religion and his honour, but he who falls into doubtful matters [eventually] falls into that which is unlawful, like the shepherd who pastures around a sanctuary, all but grazing therein...."

The Messenger of Allah (sallAllahu alayhi wa sallam) said: “Islaam is to testify that there is no deity worthy of worship but Allah and Muhammad is the Messenger of Allah, to perform prayers, to give zakaah, to fast in Ramadaan, and to make the pilgrimage to the House if you are able to do so.”

An explanation of the five pillars of Islaam: The shahada, Prayer, Zakat, Fasting and Hajj

A Fundamental hadeeth, that many scholars have said encompasses 1/3rd of this Deen/Religion...

Admonition for Muslims to strive and stay upon good and not to fall towards evil.