the Prophet said: "Whoever is overcome by vomiting, then he is not required to make up (the fast), and whoever vomits on purpose, then he must make it up."
Jami` at-Tirmidhi Book 8, Hadith 39
← Previous Hadith the Messenger of Allah said: "Three things do not break the fast of the fasting person: Cupping, vomiting, and the wet dream."

Jami` at-Tirmidhi Book 8, Hadith 38 Next Hadith → "Whoever eats or drinks forgetfully, then he has not broken (the fast), for it was only a provision that Allah provided for him."

Jami` at-Tirmidhi Book 8, Hadith 40