Why Takshaka Prevented Kashyapa From Saving Parikshit?

Janamejaya is hearing from his ministers why and how his father was killed.
He was cursed by the young rishi, Shringi, that Takshaka would kill him within seven days.
This was for insulting Shringi's father Rishi Shameeka.
We have seen how this happened and also the insult was not very intentional.
But then on the seventh day someone, a powerful brahmin called Kaashayapa had set out to save Parikshit.
Kaashyapa was very powerful.
He could cure snakebite.
Neutralize snake venom no matter how powerful it was.
This is the power of mantras.
There is a mantra for example:
यदि क्षितायुर्यदि वा परेतो यदि मृत्योरन्तिकं नीत एव।
तमा हरामि निरृतेरुपस्थादस्पार्षमेनं शतशारदाय॥
Even if your ayu is complete, even if you are gone from here, even if you are sitting near Mrityu Deva in his loka, he has taken your life, even if you are dead, I am going to get you back, revive you, to live for 100 years.
See the confidence.
Confidence in the power of mantras.
Such procedures were performed by experts in extreme situations.
Kaashypa must have been proficient in medicinal herbs and minerals as well.
Takshaka stopped him on the way.
Who are you, where are you heading to?
Don't you know?
Raja Pariskit is going to be killed today by Takshaka.
I am going to revive him after Takshaka bites him.
If I am there, the king will not die.
Takshaka said: I am Takshaka myself.
I don't think you will be able to do that.
If I bite, then that person dies.
Nobody will be able to save him.
My poison is so powerful.
Then Takshaka bit at a tree nearby.
Instantly that tree was burned down to ashes.
Now show me what you can do with your power.
Kaashaypa brought back the tree as it was before.
Takshaka realized Kaashyapa's power.
Said: tell me what you want.
How can I stop you from saving Parikshit?
Takshaka was worried about his name, about his prestige.
If he bites Parikshit and he doesn't die, then everyone will start laughing at him.
Kaashayapa said: I am going there for the money.
I will give you more money than Raja Parikshit would ever give you.
Kaashyapa took the money and went back.
Janamejaya started fuming.
Takshaka should not have done that.
He exceeded his mandate.
महानतिक्रमो ह्येष तक्षकस्य दुरात्मनः
He was supposed to kill my father.
But if someone else revived him, what was wrong?
He was under compulsion by the curse only to bite and kill my father.
Later if someone revived him, what is wrong?
No.
This was Takshaka's own plot.
He used Shringi and the curse as a reason.
This was Takshaka's own conspiracy to eliminate my father.
Otherwise, he need not have gone to such an extent.
So, I have decided, said Janamejaya, to avenge this dastardly act.
This is not just about me and my father.
Takshaka troubles everyone, see Rishi Uttanka.
Takshaka has harassed him also a lot.
He troubles everyone.
So I am going to eliminate him.
Just like how he burned my father to death with his poison, I want to burn him to death.
I want to throw him into the fire and burn him to death along with his entire clan of snakes.
Janamejaya called his purohitas and told them what he wanted.
They said: yes, there is a yaga called sarpa-satra.
With that, you can achieve what you want.
Janamejaya said: yes, I want to perform that.
A suitable yajna mandapa was built and preparation was in full swing.
At that time an expert in Vastu came there and said: looking at the measurements and time at which the construction of the mandapa was started it looks like this yaga will get stopped due to a brahmin.
Janamejaya was cautioned.
He said: no stranger should enter the yajna-mandapa without my permission.