A person came to Messenger of Allah (PBUH) and asked, “Who among people is most deserving of my fine treatment?” He (PBUH) said, “Your mother”. He again asked, ”Who next?” “Your mother”, the Prophet (PBUH) replied again. He asked, “Who next?” He (the Prophet (PBUH)) said again, “Your mother.” He again asked, “Then who?” Thereupon he (PBUH) said,” Then your father.” (Al-Bukhari)
