Shaykh ‘Ali al-Jamal (may Allah have mercy on him) said,

“Keeping the company of an ignorant (sufi) novice is like swallowing a deadly poison.

The ignorant novice, who is pleased with himself, is farther from Allah than all the common people. The common person is like a new pot: it accepts whatever is poured into it. The ignorant novice, on the other hand, is like a pot filled with tar: it is unwashable and unusable for wholesome things.”

The adab of the true seeker, page 84