Salamah bin al-Akwa said: when a man sneezed beside the prophet ﷺ, he said to him: Allah have mercy on you, but when he sneezed again, he said: The man has a cold in the head.
Hadith Referenceسنن ابي داود / كتاب الأدب / 5037
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم (2993)
Benefits and Issues: ➊ It is obligatory to respond to the first sneeze. ➋ After that, it is not obligatory, as is also indicated by Sahih Muslim. See: (Sahih Muslim, Kitab al-Zuhd, Hadith: 2993)
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 5037
´Narrated Iyas bin Salamah:` from his father: "A man sneezed in the presence of the Messenger of Allah (ﷺ) while I was present, so the Messenger of Allah (ﷺ) said: 'Yarhamukallah (May Allah have mercy upon you).' Then he sneezed a second and third time. So the Messenger of Allah (ﷺ) said: "This man is suffering from a cold.'"
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: From this it is understood that there is no need to respond after someone sneezes once or twice or more times.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 2743