When you see those who shower (undue) praise (upon others), throw dust upon their faces

Hammam ibn al-Harith reported that a person began to praise 'Uthman and then al-Miqdad sat upon his knee; he was a bulky person and began to throw pebbles upon his (flatterer's) face. Thereupon 'Uthman said:

The Prophet (may the peace and blessings of Allah be upon him) did not like flattery, because it leads to an exaggeration that calls for lying and hypocrisy, that is recognized on the face of the flatterer or in the slips of his tongue.

The Prophet (may the peace and blessings of Allah be upon him) was sometimes praised by his faithful companions as an expression of their love for him, but if one of them exaggerates in flattering the Prophet would forbid him gently and politely.