Al-Rabīʿ ibn Khuthaym said to his family: “Prepare some food for me.”
Then he called a man who was insane and began feeding him by hand, placing morsels into his mouth, while his saliva was dripping
His family said:
> You have burdened us! We prepared food for you, and then you fed this madman who doesn’t even know [what he is eating]!?
So al-Rabīʿ replied:
> But Allah knows
Source: the musannaf of ibn abi shaybah, the arabic is below
٣٧٥٨٣ - حدثنا وكيع عن الأعمش عن منذر عن الربيع أنه قال لأهله: اصنعوا لي خبيصا، فصنع فدعا رجلًا به (خبل) (١) فجعل ربيع يلقمه (ولعابه) (٢) ⦗٤٤٣⦘ يسيل، فلما أكل وخرج قال له أهله: تكلفنا، وصنعنا، ثم أطعمته؟ (٣) ما يدري هذا ما أكل؟ قال الربيع: لكن اللَّه يدري.
The food mentioned is khabees