The Messenger of Allah ﷺ said, "Whoever sips poison, his poison will be in his hand to be sipped in the Fire of Hell, where he will remain forever and ever."
حدثنا أحمد بن حنبل حدثنا أبو معاوية حدثنا الأعمش عن أبي صالح
قال رسول الله ﷺ من حسا سما فسمه في يده يتحساه في نار جهنم خالدا مخلدا فيها أبدا
[Sahih] Reported by Tirmidhi, Medicine, chapter on what has been said about one who kills himself with poison or otherwise, no. 2044, from the hadith of Abu Muawiya, and it is in the Musnad of Ahmad, 2/254. Bukhari, no. 5778, and Muslim, no. 109, also reported it from the hadith of Amash.