Hadith 1960
Abu Huraira (may Allah be pleased with him) reports that the Messenger of Allah (peace be upon him) said: "When a fasting person vomits deliberately, his fast will be broken, and when vomiting overcomes him, his fast will not be broken."
Hadith 1961
Imam Sahib narrates another report from his teacher Ali bin Hujr Sa'di that the Prophet (peace be upon him) said: "Whoever vomits unintentionally, it is not obligatory for him to make up the fast, but whoever vomits deliberately, he must make up the fast."