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