First and Foremost - be good to your Mother

Imam Sadiq (A.S) relates that once a person approached the Noble Prophet (peace be upon him and his family) and asked: “O’ Prophet of Allah! Towards whom should I exhibit goodness and kindness?”‌ The Noble Prophet replied: “Towards your mother.”‌ The man then asked: “And after that towards whom?”‌ The Noble Prophet again said: “Your Mother.”‌ He asked again: “And then?”‌ Once again, he replied: “Your mother.”‌ For the fourth time the man asked: “And then?”‌ This time he said: “(Then towards) Your father.”‌

Biharul Anwar, Volume 74, Page 49

Other links:

Obedience towards One’s Parents

Kindness to Parents

Looking at Parents