Ata' bin al-Sa'ib narrates from his father, from his grandfather, that the Prophet (peace and blessings be upon him) said: "Whoever is prompted at the time of death to bear witness to 'La ilaha illallah' (and he says this word) will enter Paradise."
Al-Tabarani recorded it in al-Mu'jam al-Kabir. The narrator named Ata' has been criticised.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجنائز / 3914