‘Iyad ibn Himar reported: The Messenger of Allah, peace and blessings be upon him, said:

إِنَّ اللَّهَ أَوْحَى إِلَيَّ أَنْ تَوَاضَعُوا حَتَّى لَا يَبْغِيَ أَحَدٌ عَلَى أَحَدٍ وَلَا يَفْخَرَ أَحَدٌ عَلَى أَحَدٍ

Verily, Allah has revealed to me that you must be humble towards one another, so that no one oppresses another or boasts to another.

Source: Ṣaḥīḥ Muslim 2865, Grade: Sahih

Abu Nadrah reported: The Messenger of Allah, peace and blessings be upon him, said:

يَا أَيُّهَا النَّاسُ أَلَا إِنَّ رَبَّكُمْ وَاحِدٌ وَإِنَّ أَبَاكُمْ وَاحِدٌ أَلَا لَا فَضْلَ لِعَرَبِيٍّ عَلَى أَعْجَمِيٍّ وَلَا لِعَجَمِيٍّ عَلَى عَرَبِيٍّ وَلَا لِأَحْمَرَ عَلَى أَسْوَدَ وَلَا أَسْوَدَ عَلَى أَحْمَرَ إِلَّا بِالتَّقْوَى أَبَلَّغْتُ

O people, your Lord is one and your father Adam is one. There is no favor of an Arab over a foreigner, nor a foreigner over an Arab, and neither white skin over black skin, nor black skin over white skin, except by righteousness. Have I not delivered the message?

Source: Musnad Aḥmad 23489, Grade: Sahih

Sahl ibn Sa’d reported: The Messenger of Allah, peace and blessings be upon him, said:

اللَّهُمَّ اغْفِرْ لِقَوْمِي فَإِنَّهُمْ لا يَعْلَمُونَ

O Allah, forgive my people for they do not know.

Abu Hatim, may Allah be pleased with him, said:

يَعْنِي هَذَا الدُّعَاءُ أَنَّهُ قَالَ يَوْمَ أُحُدٍ لَمَّا شُجَّ وَجْهُهُ

This supplication was said during the battle of Uhud when they slashed his face.

Source: Ṣaḥīḥ Ibn Ḥibbān 973, Grade: Hasan

Al-Zubayr ibn ‘Awwam reported: The Messenger of Allah, peace and blessings be upon him, said:

دَبَّ إِلَيْكُمْ دَاءُ الْأُمَمِ قَبْلَكُمْ الْحَسَدُ وَالْبَغْضَاءُ وَالْبَغْضَاءُ هِيَ الْحَالِقَةُ حَالِقَةُ الدِّينِ لَا حَالِقَةُ الشَّعَرِ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَا تُؤْمِنُوا حَتَّى تَحَابُّوا أَفَلَا أُنَبِّئُكُمْ بِشَيْءٍ إِذَا فَعَلْتُمُوهُ تَحَابَبْتُمْ أَفْشُوا السَّلَامَ بَيْنَكُمْ

Lurking towards you are the diseases of the nations before you. Envy and hatred are the razor. I do not say they shave hair, but rather they shave the religion. By the One in whose hand is my soul, you will not enter Paradise until you have faith and you will not have faith until you love each other. Shall I tell you what can affirm that for you? Spread peace between yourselves.

Source: Sunan al-Tirmidhī 2510, Grade: Sahih

Abdullah ibn Amr reported: A man asked the Prophet, “Which Islam is best?” The Messenger of Allah, peace and blessings be upon him, said:

تُطْعِمُ الطَّعَامَ وَتَقْرَأُ السَّلاَمَ عَلَى مَنْ عَرَفْتَ وَمَنْ لَمْ تَعْرِفْ

To feed the hungry and to greet with peace those you know and those you do not know.

Source: Ṣaḥīḥ al-Bukhārī 28, Grade: Muttafaqun Alayhi

Ibn Mas’ud reported: The Messenger of Allah, peace and blessings be upon him, said:

لَيْسَ الْمُؤْمِنُ بِالطَّعَّانِ وَلَا اللَّعَّانِ وَلَا الْفَاحِشِ وَلَا الْبَذِيءِ

The believer does not insult others, does not curse others, is not vulgar, and is not shameless.

Source: Sunan al-Tirmidhī 1977, Grade: Sahih

Abu Huraira reported: It was said, “O Messenger of Allah, pray against the idolaters!” The Messenger of Allah, peace and blessings be upon him, said:

إِنِّي لَمْ أُبْعَثْ لَعَّانًا وَإِنَّمَا بُعِثْتُ رَحْمَةً

Verily, I was not sent to invoke curses, but rather I was only sent as mercy.

Source: Ṣaḥīḥ Muslim 2599, Grade: Sahih

Abdullah ibn Amr reported: The Messenger of Allah, peace and blessings be upon him, said:

الرَّاحِمُونَ يَرْحَمُهُمْ الرَّحْمَنُ ارْحَمُوا مَنْ فِي الْأَرْضِ يَرْحَمْكُمْ مَنْ فِي السَّمَاءِ

The merciful will be shown mercy by the Most Merciful. Be merciful to those on the earth and the One in the heavens will have mercy upon you.

Source: Sunan al-Tirmidhī 1924, Grade: Sahih

Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said:

كُنْ وَرِعًا تَكُنْ أَعْبَدَ النَّاسِ وَكُنْ قَنِعًا تَكُنْ أَشْكَرَ النَّاسِ وَأَحِبَّ لِلنَّاسِ مَا تُحِبُّ لِنَفْسِكَ تَكُنْ مُؤْمِنًا وَأَحْسِنْ جِوَارَ مَنْ جَاوَرَكَ تَكُنْ مُسْلِمًا وَأَقِلَّ الضَّحِكَ فَإِنَّ كَثْرَةَ الضَّحِكِ تُمِيتُ الْقَلْبَ

Be devout and you will be the most pious of people. Be content and you will be the most grateful of people. Love for people what  you love for yourself and you will be a believer. Behave well with your neighbors and you will be a Muslim. Laugh less, for too much laughter will deaden the heart.

Source: Sunan Ibn Mājah 4217, Source: Sahih