Hisnul Muslim 151

When the sick have renounced all hope of life

لَا إِلَهَ إِلَّا اللَّه إِنَّ لِلمَوْتِ لَسَكَرَاتٍ

Laa 'ilaaha 'illallaahu 'inna lilmawti lasakaraatin.

There is none worthy of worship but Allah, surely death has agonies.