A well-instructed disciple of the noble ones, when endowed with these four qualities* [the factors of stream-entry]:
1. Has no terror
2. No trepidation
3. No fear at death with regard to the next life
— SN 55.27
Then there is the case of the person who has no doubt or perplexity, who has arrived at certainty with regard to the True Dhamma. Then he comes down with a serious disease. As he comes down with a serious disease, the thought occurs to him:
I have no doubt or perplexity.
I have arrived at certainty with regard to the True Dhamma.
He doesn't grieve, isn't tormented; doesn't weep, beat his breast, or grow delirious.
This, too, is a person who, subject to death, is not afraid or in terror of death.
— AN 4.184