On the recommendation to bless someone who sneezes when he praises Allah and dislike of doing it if he has not praised Allah

Riyad as-Salihin (The Meadows of the Righteous)

by Imam Nawawi

142. Chapter: On the recommendation to bless someone who sneezes when he praises Allah and dislike of doing it if he has not praised Allah; clarification of the adab of blessing the sneezer, sneezing, and yawning

878. Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "Allah loves sneezing and hates yawning. When one of you sneezes and praises Allah Almighty, it is a duty for every Muslim who hears him to say to him, 'May Allah have mercy on you.' Yawning comes from Shaytan. When one of you yawns, he should control it as much as possible. When one of you yawns, Shaytan laughs at him." [al-Bukhari]

879. Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "When one of you sneezes, he should say, 'Praise be to Allah,' and his brother or companion should say to him, 'May Allah have mercy on you.' Then he should say, 'May Allah guide you and put your affairs in order.'" [al-Bukhari]

880. Abu Musa said, "I heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'When one of you sneezes, he should praise Allah and you should wish him mercy. If he does not praise Allah, do not wish him mercy." [Muslim]

881. Anas said, "Two men sneezed in the presence of the Prophet, may Allah bless him and grant him peace, and he wished one of them mercy, but did not wish the other one mercy. The one who had not been wished mercy said, 'So-and-so sneezed and you wished him mercy, but I sneezed and you did not wish me mercy!' He said, 'This one praised Allah and you did not praise Allah.'" [Agreed upon]

882. Abu Hurayra said, "When the Messenger of Allah, may Allah bless him and grant him peace, sneezed, he would put his hand or his garment over his mouth and lower - or muffle - the noise. (The transmitter was unsure.)" [Abu Dawud and at-Tirmidhi]

883. Abu Musa said, "The Jews used to make themselves sneeze in the presence of the Messenger of Allah, may Allah bless him and grant him peace, hoping that he would say to them, 'May Allah have mercy on you.' But he would say, 'May Allah guide you and put you right.'" [Abu Dawud and at-Tirmidhi]

884. Abu Sa'id al-Khudri reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "When one of you yawns, he should put his hand over his mouth. For Shaytan might enter it." [Muslim]