Malik related to me from Abdullah ibn Dinar from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "If a man says to his muslim brother, 'O kafir!' it is true about one of them."
Muwatta Malik Book 56, Hadith 1
← Previous Hadith Malik related to me from Abdullah ibn Dinar that Abdullah ibn Umar wrote to Abd al-Malik ibn Marwan, making an oath of allegiance. He wrote, "In the name of Allah, the Merciful, the Compassionate. To the slave of Allah, Abd al-Malik, the amir al-muminin, Peace be upon you. I praise Allah to you. There is no god but Him. I acknowledge your right to my hearing and my obedience according to the sunna of Allah and the sunna of His Prophet, in what I am able."

Muwatta Malik Book 55, Hadith 3 Next Hadith → Malik related to me from Suhayl ibn Abu Salih from his father from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "When you hear a man say, 'The people are ruined,' he himself is the most ruined of them all."

Muwatta Malik Book 56, Hadith 2