In an anecdote about Sufism, showing that its knowledge is solely on spiritual taste, is that a student of the famous Muhiyyadin Ibn Arabi (d.1240 CE) came to him to say:
People are condemning us for our knowledge and asking us for proof for it.
Ibn Arabi responded with the following advice:
“If anyone demands a proof or demonstration for knowledge of divine secrets, then say to him: what is the proof for the sweetness of honey? He must respond by saying that this knowledge can only come by means of taste. Say the same is knowledge of divine secrets.”
Tasawwuf by Dr Ali Gomaa