The Messenger of Allah ﷺ said something to this effect, and I believe he said regarding the fifth time, "If he drinks it, then kill him."
حدثنا موسى بن إسمعيل حدثنا حماد عن حميد بن يزيد عن نافع
أن رسول الله ﷺ قال بهذا المعنى قال وأحسبه قال في الخامسة إن شربها فاقتلوه
No references are available.
[Its isnad is daif] Ahmad reported it (2/136) through Hammad bin Salama, with this same chain, and its chain is daif because of the unknown status of Humayd bin Yazid. The correct reading is "in the fourth" instead of "the fifth."