الإمامُ الصّادقُ (عَلَيهِ الّسَلامُ) : مَن رأى أخاهُ عَلى أمرٍ يَكرَهُهُ فَلم يَرُدَّه عَنهُ وَهُو يَقدِرُ علَيهَ فقد خانَهُ. 
‪Imam al-Sadiq (AS) said, ‘A man who observes bad behavior in his brother without forbidding him from it – whilst he is able to – has indeed betrayed him.’[Ibid. v. 75, p. 65, no. 2]