Al-Adab Al-Mufrad #341

'Ata' ibn Abi Rabah reported that a man was praising another man in the presence of Ibn 'Umar. Ibn 'Umar began to throw dust towards his mouth. He said, "The Messenger of Allah, may Allah bless him and grant him peace, said, 'When you see those who praise people, throw dust in their faces.'"