When you see those who praise others, throw dust upon their faces

Al-Miqdād (may Allah be pleased with him) reported that a man was exaggerating in his praise of ‘Uthmān (may Allah be pleased with him). Al-Miqdād sat on his knees, gathered up small stones, and began throwing them at the face of the flatterer. ‘Uthmān asked him why he did that, so he informed him that the Prophet (may Allah's peace and blessings be upon him) ordered that when we see someone who showers praise upon others, we should throw dust at their faces.