Imam Moosa Al-Kadhim (as) and Knowledge of unseen (Ilm-e-Ghaib):

One day Haroon Rasheed sent some robes to Ali bin Yaqtin to honour
him. Among their number was a black woolen cloak adorned with gold
like the robes of kings. Ali bin Yaqtin dispatched those robes to Imam
Moosa Al-Kadhim (as). Among their number he (also) sent that cloak
adorned with gold. Ali bin Yaqtin added some money which he had
already prepared specifically for him as the fifth of his money (Khums
- tax for the Imams) which he was going to pay him.
When that reached Imam Moosa Al-Kadhim (as), he accepted the money and
the robes but returned the cloak by the hand of the messenger to Ali
bin Yaqtin. Imam Musa Al-Kadhim (as), wrote to him: "Keep it and do
not let it leave your hands. For an event will occur to you because of
it when you will have the need of it with him (Haroon Rasheed)."
Ali bin Yaqtin was suspicious about it being returned to him and did
not understand the reason for that. Some time later, Ali bin Yaqtin
changed (his attitude) towards a servant who had a special position
with him and he left his service.
The servant knew about Ali bin Yaqtin's inclination towards Imam Musa
Al-Kadhim (as). He was acquainted with the money, robes and other
things (Ali bin Yaqtin) had sent to (Imam Musa Al-Kadhim (as)) on
every occasion. He (went and) informed on him to Haroon Rasheed. He
told (Haroon Rasheed) that (Ali bin Yaqtin) maintained the Imamate of
Imam Musa Al-Kadhim (as) and paid him a fifth of his money each year,
and also that he had given him the cloak with which the Commander of
the faithful (Haroon Rasheed) had honoured him at such-and-such a
time. Haroon Rasheed burned with anger and was furious. He declared:
"I will expose this situation. If the matter is as you say, his life
will be destroyed."
Abbasid Caliph, Haroon Rasheed immediately sent for Ali bin Yaqtin to
be brought. When he appeared before him, Haroon Rasheed said: "What
have you done with the cloak which I bestowed upon you?"
"Commander of the faithful," (Ali bin Yaqtin) replied, "I still have
it in a sealed chest and there I keep perfume with it. In the mornings
I open it and look at it to gain blessings from it. I kiss it and then
put it back in its place. Every night I do the same thing."
"Bring it, immediately," Haroon Rasheed ordered.
"Yes, Commander of the faithful," he answered. Ali bin Yaqtin summoned
one of his servants and told him: "Go to such-and-such a room in my
house. Take the key for it from my custodian and open it. Open
such-and-such a box and bring me the sealed chest which is in it."
It was not long before the servant returned with the chest still
sealed. Ali bin Yaqtin put it before Haroon Rasheed and told him to
break the seal and open it. When Haroon Rasheed opened it, he saw the
cloak in it folded and laid out in perfume.
Haroon Rasheed's anger became pacified and he said to Ali bin Yaqtin:
"Return it to its place and go away righteously. I will never
disbelieve you again on the word of an informer."
Haroon Rasheed ordered a magnificent gift to be sent after him and he
had the informer flogged with a thousand lashes. After he had been
flogged about a hundred lashes, informer died.