ENOfficial
Narrated Abdullah ibn Mas'ud: If anyone helps his people in an unrighteous cause, he is like a camel which falls into a well and is pulled out by its tail.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا النُّفَيْلِيُّ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا سِمَاكُ بْنُ حَرْبٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ، عَنْ أَبِيهِ، قَالَ مَنْ نَصَرَ قَوْمَهُ عَلَى غَيْرِ الْحَقِّ فَهُوَ كَالْبَعِيرِ الَّذِي رُدِّيَ فَهُوَ يُنْزَعُ بِذَنَبِهِ .
sunnah.com