The Messenger of Allah ﷺ recited this verse, "Fear Allah as He should be feared, and do not die except as Muslims" [Al Imran 3:102]. The Messenger of Allah ﷺ then said, "If a single drop of Zaqqum were to fall upon this world, it would ruin the livelihoods of its people. So how must it be for the one whose food it is?"
حدثنا محمود بن غيلان حدثنا أبو داود أخبرنا شعبة عن الأعمش عن مجاهد
أن رسول الله ﷺ قرأ هذه الآية {اتقوا الله حق تقاته ولا تموتن إلا وأنتم مسلمون} قال رسول الله ﷺ لو أن قطرة من الزقوم قطرت في دار الدنيا لأفسدت على أهل الدنيا معايشهم فكيف بمن يكون طعامه
[Its isnad is sahih]. Ibn Majah also narrated it in the chapter on Zuhd, section on the description of Hellfire, hadith 4325, from the hadith of Shubah with the same wording. Ibn Hibban graded it sahih (al-Ihsan): 7427, and Hakim: 2/294, 451, saying it meets the criteria of the two Shaykhs, and Dhahabi agreed with him. It is also found in Musnad Abu Dawud Tayalisi (2643).