Ziyad bin Kusayb al-Adawi (may Allah have mercy on him) says that Abdullah bin Amir (may Allah be pleased with him) used to deliver the sermon to the people while wearing fine (thin) clothes, with his hair combed. One day he prayed and then went in; Abu Bakrah (may Allah be pleased with him) was sitting beside the pulpit. Mirdas Abu Bilal said: Do you not see the ruler, who wears fine clothes and imitates the sinners? When Abu Bakrah (may Allah be pleased with him) heard this, he said to his son al-Usayli': Call Abu Bilal. He called him, and he said: I have heard what you said just now about the ruler. I heard the Prophet (peace and blessings be upon him) say: "Whoever honours the ruler, Allah will honour him; and whoever disgraces the ruler, Allah will disgrace him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16659