The Forty Hadith of Al-Nawawi.
On the authority of Abu Hurayrah (may Allah be pleased with him), who said:
The Messenger of Allah (peace and blessings of Allah be upon him) said:
"Do not envy one another,
do not artificially inflate prices against one another,
do not hate one another,
do not turn your backs on one another,
and do not underbid one another in transactions.
Rather, be servants of Allah and brothers to each other.
A Muslim is a brother to a fellow Muslim:
he does not wrong him,
nor abandon him,
nor lie to him,
nor look down upon him.
Piety is right here,"
and he pointed to his chest three times.
"It is sufficient evil for a person
to hold his Muslim brother in contempt.
Everything belonging to a Muslim is inviolable to another Muslim:
his blood, his wealth, and his honor."
Related by Muslim.
This hadith illustrates the foundation of social relationships in Islam,
which are brotherhood, love, and purity of heart.
For the Prophet (peace be upon him) strictly forbade
everything that corrupts mutual affection among people,
such as envy, deception, and mutual hatred,
and he commanded that Muslims be brothers who love and support one another.