Mishkat al-Masabih 3695
Ziyad b. Kusaib al-‘Adawi said:
I was with Abu Bakra under Ibn ‘Amir’s pulpit when he was preaching and wearing thin garments. Abu Bilal said, “Look at our governor wearing the garments of profligates,” whereupon Abu Bakra told him to be quiet, for he had heard God’s Messenger say, “He who despises God’s ruler in the earth will be despised by God.” 

Tirmidhi transmitted it, saying this is a hasan gharib tradition.
وَعَن زِيادِ بنِ كُسَيبٍ العَدَوِيِّ قَالَ: كُنْتُ مَعَ أَبِي بَكْرَةَ تَحْتَ مِنْبَرِ ابْنِ عَامِرٍ وَهُوَ يَخْطُبُ وَعَلَيْهِ ثِيَابٌ رِقَاقٌ فَقَالَ أَبُو بِلَال: انْظُرُوا إِلَى أَمِير نايلبس ثِيَابَ الْفُسَّاقِ. فَقَالَ أَبُو بَكْرَةَ: اسْكُتْ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُول: «مَنْ أَهَانَ سُلْطَانَ اللَّهِ فِي الْأَرْضِ أَهَانَهُ اللَّهُ» رَوَاهُ التِّرْمِذِيُّ وَقَالَ: هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ