The Prophet ﷺ announced to the people the death of Najashi on the very day he died, then took them out to the prayer ground, arranged them in rows, prayed over him, and pronounced four takbirs.
أخبرنا سويد بن نصر قال أنبأنا عبد الله عن مالك عن ابن شهاب عن سعيد بن المسيب
أن النبي ﷺ نعى للناس النجاشي اليوم الذي مات فيه ثم خرج بهم إلى المصلى فصف بهم فصلى عليه وكبر أربع تكبيرات
Bukhari narrated it in the Book of Funerals, chapter on a man announcing the death himself to the deceased's family, hadith no. 1245, and Muslim, hadith no. 951, see the previous hadith, from the hadith of Malik through the same chain. It is also in Al-Kubra, hadith no. 2098, and in Muwatta (narrated by Yahya), 1/226.