It wasnarrated that Abu Sa'eed Al-Khudri said:
"The Messenger ofAllah(ﷺ) said: 'Urge your dying ones to say: "La ilaha illallah." (RU)
English reference (RU): Vol. 1, Book 6, Hadith 1445 (RU)
Arabic reference (RU): Book 6, Hadith 1512 (RU)