During Salah, should a person say: "Al-hamdu lillah (All praise is due to Allah)" upon sneezing and "A`udhu-Billahi mina Al-Shaytan-ir-Rajim (I seek refuge with Allah from the accursed Satan)" upon yawning?
If during Salah a person sneezes, they should say: "Al-hamdu lillah," but they should not say: "A`udhu-Billahi mina Al-Shaytan-ir-Rajim" upon yawning during Salah, for no report has been narrated to that effect. Moreover, the person who sneezes during Salah should neither answer Tashmit (i.e. Respond to the invocation prescribed to be said to a sneezer: "Yarhamuk Allah [May Allah be merciful to you]'') nor reply to a person who greets them; rather, they should only gesture with their hand. This is based on the general ruling implied in the Hadith in which the Prophet (peace be upon him) said:
Salah occupies one's full attention.
This is also based on the Hadith narrated on the authority of
Mu`awiyah ibn Al-Hakam Al-Sulamy (Part No. 7; Page No. 31) in regards to saying to a worshiper who sneezed during Salah: "Yarhamuk Allah," the Prophet (peace be upon him) instructed him:
In this Salah nothing of human speech is permitted; it is only Tasbih (glorification of Allah), Takbir (magnification of Allah), and recitation of the Qur'an.
Muslim in his Sahih [Authentic Hadith Book])
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family and Companions.