Imam al-Hadi (a.s.) was asked, ‘Why do these Muslims hate death?’ He said, ‘Because they ignore it, and therefore, they hate it. If they knew it and were from the devotees of Allah, they would surely love it and know that the afterlife would be better than the worldly life.’ Then Imam al-Hadi (a.s.) turned to his companions and said, ‘Why do a child and an insane refrain from drug that recovers their bodies and relieves them from pain?’
They said, ‘Because they ignore the benefit of drug.’
He said, ‘I swear by Him Who had sent Muhammad with the truth as prophet, whoever prepares himself to death, it would be better for him than this curative drug. If they know what bliss death gets to, they will love it and call for it more than a sane, determined man when calling for drug to cure his diseases and get safety.’
one day Imam al-Hadi (a.s.) visited a sick companion and saw him cry fearing from death. He said to him, ‘O Abdullah (slave of Allah), you fear from death because you do not know it. If you become dirty and filthy, and you suffer from this dirt and filth that cause you sores and mange, and then you know that washing in the bathroom will relieve all that, do you not want to go to the bathroom and remove all that from you, or you hate to do that and you let filth, sores, and mange on you?’
The sick man said, ‘O yes, son of the messenger of Allah, may Allah have blessing and peace on you and your household.’
Imam al-Hadi (a.s.) said, ‘Death is that bathroom. It is the last thing remaining for you to wash your guilt and purify you from your sins. If you come to it and be its neighbor, you shall be free from every distress, grief, and pain, and shall get to every happiness and delight.’ The sick man was calm. He submitted to death and pleased with the fate of Allah. ( Ma’ani al-Akhbar by as-Saduq.)
Reference : The Life of Imam ALI bin Muhammad AL-HADI