There’s a side story of RAMAYANA.
This is when Lord HANUMAN goes to LANKA on the surveillance mission meets MATA SITA, but allows himself to be captured so that he gets to meet RAVANA.
The meeting is a diplomatic disaster. Ravana wishes to send a strong message by killing Hanuman but for decided otherwise because of his god fearing brother VIBHISHAN.
But he still wants to send a message to his enemy (LORD RAMA). Cause HANUMAN looked to be of the monkey / ape family, they decide to wrap the entire length of the tail with a cloth soaked in oil and light it up.
So every time they would wrap a cloth it would be a little short, and again they would try and it would be little short and this kept happening until there was no cloth in the entire lanka. They lite the fire at last.
All of us know LORD HANUMAN burned down Lanka.. But what they don’t know is that that, on his way out of RAVANA’s palace, LORD HANUMAN gets to meet SHANIDEV in RAVANA’s dungeon / jail. Ravana was so powerful he captured SHANIDEV too.
So SHANIDEV is crying out for help, and LORD HANUMAN hears it and reaches out to him even though his tail is on fire.
Shanidev requests LORD HANUMAN to save him from RAVANA. LORD HANUMAN agrees.
Shanidev has a slow gait and he’s not much of a warrior and he’s so scared of RAVANA that he wouldn’t even step on the LANKA SOIL.
So he requests HANUMAN if he can be carried on the head. Cause otherwise there’s chance of getting hurt. HANUMAN agrees.
So SHANIDEV sits on HANUMANS head.
But while HANUMAN is making his way out and burning down the city he’s attacked by RAVANA’s rakshasa soldiers and where do they hit HANUMAN? On the head of course. Cause you just need one deadly blow on the head to finish off the being.
But because SHANIDEV is sitting on HANUMANJI’s head, he’s getting the brunt of the blows.
So once HANUMANJI has made his way out of LANKA and SHANIDEV feels safe, SHANIDEV gets down from his head and thanks HANUMANJI for saving him from the clutches of RAVANA.
But SHANIDEV is badly hurt, so lord HANUMAN applies MUSTARD OIL (SESAME)/TIL OIL on SHANIDEV’s bruises to heal.
That’s the reason TIL OIL is offered to SHANIDEV.
As a reciprocation for saving his life and caring for his bruises SHANIDEV tells HANUMANJI that he will NOT TRIUBLE ANYONE WHO PRAYS TO LORD HANUMAN. That’s why doing HANUMAN CHALISA will save you from the ill effects of SATURN.