Forbidding from associating with the Sufis

Al-Husayn bin Abul Khattab said, ‘One day, I was with Abul Hasan al-Hadi (a.s.) in the mosque of the Prophet (a.s.) when some of his companions, among whom was Abu Hashim al-Ja’fari, came to him. Abu Hashim was an eloquent man and had a high position near Imam al-Hadi (a.s.). While we were standing, a group of Sufis came into the mosque. They sat in a corner of the mosque and began saying “la ilaha illallah; there is no god but Allah”. Imam al-Hadi (a.s.) turned towards his companions and said to them, ‘Do not pay attention to these deceivers for they are allies of the Devils and destroyers of the bases of religion. They become ascetic to relieve their bodies and watch to hunt cattle…they do not practice rites except to deceive people, and do not decrease food except to…cheat the fool…their worships are but dancing and clapping, and their praises are but singing. No one follows them except the stupid, and no one believes in them except the fool. Whoever went to visit any of them alive or dead as if he went to visit Satan and idolaters, and whoever supported any of them, as if he supported, Mo’awiya, Yazid, and Abu Sufyan…’ 
One of the companions said, ‘Even if he acknowledges your rights?’
Imam al-Hadi (a.s.) scolded him and shouted, ‘Do not say that! He, who acknowledges our rights, does not disobey us. Do you not know that they are the worst group of Sufis, though all Sufis are dissentient to us and their way is contrary to ours? They are but Christians and magi of this nation. They do their best to put out the light of Allah with their mouths, and Allah will not consent save to perfect His light, though the unbelievers are averse…’