What a dying person should recite during death?

What to encourage the dying person to say
 

He will enter Paradise he who dies with the last words saying:

لا إلهَ إلاّ اللّه

153. Laa 'ilaaha 'illallaahu.

There is none worthy of worship but Allah. 

Reference: Abu Dawud 3/190. See also Al-Albani, Sahihul-Jami' As-Saghir 5/432.