The Messenger of Allah (peace be upon him and his family) said: “Every righteous child who casts a look of mercy and affection upon his parents shall be granted, for every look of his, rewards equivalent to that of an accepted Hajj.” Those around the Prophet questioned: “O’ Prophet of Allah! Even if he were to look at them a hundred times a day?” The Messenger of Allah (peace be upon him and his family) replied: “Indeed! Allah is the Greatest and Most Kind.”
(Biharul Anwar, Volume 74, Page 73)The Messenger of Allah (peace be upon him and his family) said: “One who desires a long life and an increase in livelihood should exhibit goodness towards his parents and establish bonds of kinship (with his relatives).”
(Kanzul `Ummal, Volume 16, Page 475)

Benefits of Kindness to Parents:
Hanan Ibn Sudair narrates: “We were in the presence of Imam as-Sadiq (peace be upon him) and amidst us was Muyassir. During the discussion, the topic of silah rahim (establishing bonds of kinship with one’s relatives) came to the fore, whereupon] the Imam (peace be upon him), [addressing Muyassir], said: ‘O’ Muyassir! On several occasions, your end had drawn near, but on each occasion, Allah delayed your death due to your acts of silah rahim with your relatives. If you desire to have your life-span increased, exhibit goodness and kindness towards your parents.’”
(Biharul Anwar, Volume 74, Page 84)

Evil Parents And Kindness:
Imam Muhammad al-Baqir (peace be upon him) has said: “There are three things which Allah, the Mighty and the Glorious has not permitted anyone to forsake: returning a trust to its owner, irrespective of whether he is a good person or an evil one; fulfilling one’s promises and covenants, irrespective of whether it has been made to a good person or an evil one; being good and kind towards one’s parents, irrespective of whether they are good or evil.”
(Biharul Anwar, Volume 74, Page 56)

Visiting the Graves of Parents:
It has been narrated that the Messenger of Allah (peace be upon him and his family) said: “Whoever visits the graves of his parents or one of them every Friday, Allah shall forgive his sins and shall regard him to be of those who had been kind to his parents.”
(Kanzul `Ummal, Volume 16, Page 468)

Forgiveness of Sins:
Imam Zainul `Abidin (peace be upon him) relates: “Once a person approached the Messenger of Allah (peace be upon him and his family) and said: ‘O’ Prophet of Allah! I have committed every known evil act. Is there a chance that I may be forgiven?’ The Messenger of Allah asked him: ‘Are any of your parents still alive?’ The man replied: ‘My father.’ He said to him: ‘Go and be good and kind to him.’ When he left, the Messenger of Allah muttered: ‘If only his mother had been alive.’”
(Biharul Anwar, Volume 74, Page 82)

No Entry into Paradise!
Imam as-Sadiq (peace be upon him) has said: “The person who has been disowned by his parents, one who consumes intoxicants and one who does acts of goodness towards others but imposes obligations upon them shall never enter into Paradise.”
(Biharul Anwar, Volume 74, Page 74)

The Imam’s Displeasure:
Imam Muhammad al-Baqir (peace be upon him) relates: “Once my father saw a person and his son walking together. As they walked, the son was leaning against the arm of his father. (This act of the son was so abhorrent and infuriating to my father that) he (peace be upon him) never spoke to him throughout his life.”
(Biharul Anwar, Volume 74, Page 64)

On Behalf of Parents:
Imam as-Sadiq (peace be upon him) had said: “What prevents a person from doing good to his parents – whether alive or dead – by offering prayers, giving charity, performing Hajj on behalf of them, (knowing that) the rewards of these acts are also granted to him, in addition to his parents? Besides, due to his good deeds and prayers (for them), Allah, the Mighty and the Glorious, shall grant him abundant good.”
(Biharul Anwar, Volume 74, Page 46)

Lesson from this topic:
Responsibilities Towards One’s Parents
Imam as-Sadiq (peace be upon him) has said (in regards to one’s parents): “Do not cast your gaze upon them except with love and compassion; do not raise your voice above theirs; do not raise your hands above theirs; do not walk ahead of them.”
(Biharul Anwar, Volume 74, Page 79)