and all that they needed for dealing with people: dutifulness to parents, maintaining kinship bonds, good companionship and neighborliness, and the like.

He also taught them how to conduct their mutual transactions—buying and selling, pledging and redeeming, leasing and hiring, giving and receiving gifts, and everything of that sort.

So comprehensive was his instruction that Abū Dharr (may Allah be pleased with him) said, “The Messenger of Allah ﷺ passed away, and there is not a bird flapping its wings in the sky except that he had told us some knowledge about it.”

Likewise, Ṣaḥīḥ Muslim relates from Salmān (may Allah be pleased with him) that someone asked him, “Has your Prophet taught you everything, even how to relieve yourselves?” He replied, “Indeed. He forbade us to face the qiblah while defecating or urinating,” and he went on to recount the rest of the narration.

All this comes in addition to the foundations underlying these acts of worship, ethics, and transactions—namely, what the servants believe about their Lord and Deity: His essence, His names, His attributes, His actions, and the universal and prescriptive rulings that flow from that, founded upon perfect wisdom and utmost mercy.

The Companions took all of this from him as a pure, untainted spring built upon complete tawḥīd (monotheism), which rests on two fundamental pillars: negation and affirmation.

• Affirmation: affirming for Allah, exalted be He, what is due to Him—His lordship, divinity, names and attributes, and actions.
• Negation: denying that anyone besides Allah has any share in what is due solely to Him.

Those who followed them with excellence—whether they met the Companions or came after them from the Imams of guidance who earned Allah’s pleasure—remained upon this way, as Allah the Exalted says: “And the foremost, the first of the Emigrants and the Helpers, and those who followed them…”