Anas (may Allah be pleased with him) narrates: Two men sneezed in the presence of the Prophet (peace and blessings of Allah be upon him). He responded to the sneeze of one of them but did not say anything to the other. The latter said, "O Messenger of Allah! You prayed for him but did not pray for me." The Prophet (peace and blessings of Allah be upon him) said: "Because he said 'Alhamdulillah' (All praise is due to Allah), but you did not say 'Alhamdulillah'." Agreed upon.