Abdullah al-Bahi, the freed slave (mawla) of Mus'ab bin al-Zubayr (may Allah have mercy on him), said: Some riders stopped at Sayyiduna Uthman (may Allah be pleased with him), and they extolled and praised him - and Sayyiduna Miqdad bin al-Aswad (may Allah be pleased with him) was present there. He took a handful of dust from the ground and threw it in their faces, and said: I heard the Messenger of Allah (peace and blessings be upon him) say: "When you see the flatterers, throw dust in their faces."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17716