لَا إِلَهَ إِلَّا اللَّهُ وَاللَّهُ أَكْبَرُ، لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ، لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ، لَا إِلَهَ إِلَّا اللَّهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ، لَا إِلَهَ إِلَّا اللَّهُ وَلَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ

Laa 'ilaaha 'illAllahu wAllahu 'Akbar, laa 'ilaaha 'illAllahu wahdahu, laa 'ilaaha 'illAllahu wahdahu laa shareeka lahu, laa 'ilaaha 'illAllahu lahul-mulku wa lahul-hamdu, laa 'ilaaha 'illAllahu wa laa hawla wa laa quwwata 'illaa billaah

There is none worthy of worship but Allah, Allah is the Most Great. None has the right to be worshipped but Allah alone. None has the right to be worshipped but Allah alone, Who has no partner. There is none worthy of worship but Allah, His is the dominion and His is the praise. There is none worthy of worship but Allah, there is no power and no might but by Allah. Abu Saeed Khudri (RA) and Abu Hurairah (RA) said that the Messenger of Allah (ﷺ) said that when a servant says these words, Allah responds to him and if someone says these words while he is ill and then dies, the fire will not touch him.

Reference: Sahih. Tirmidhi: 3430