[ALLAH’S Quran – 31:14 ] “And (Allah says), “We have enjoined on every human being concerning his parents (to be good to them). His mother is worn and wasted in bearing him and it takes her two years to wean him. And give thanks to Me and to your parents. To Me shall be the (ultimate) return (of you all).”

The Prophet (pbuh) has said:
[Bukhari, Book #73, Hadith #1] “Narrated Al-Walid bin ‘Aizar: I heard Abi Amr ‘Ash-Shaibani saying, “The owner of this house.” he pointed to ‘Abdullah’s house, “said, ‘I asked the Prophet ‘Which deed is loved most by Allah?” He replied, ‘To offer prayers at their early (very first) stated times.’ ” ‘Abdullah asked, “What is the next (in goodness)?” The Prophet said, “To be good and dutiful to one’s parents,” ‘Abdullah asked, “What is the next (in goodness)?” The Prophet said, To participate in Jihad for Allah’s Cause.” ‘Abdullah added, “The Prophet narrated to me these three things, and if I had asked more, he would have told me more.”

[Muslim, Book #001, Hadith #0151] “It is narrated on the authority of ‘Abdullah b. Mas’ud that he observed. I asked the Messenger of Allah (may peace be upon him) which deed was the best. He (the Holy Prophet) replied: Prayer at its appointed hour. I (again) said: Then what? He (the Holy Prophet) replied: Kindness to the parents. I (again) said: Then what? He replied: Earnest endeavour (Jihad) in the cause of Allah. And I would have not ceased asking more questions but out of regard (for his feelings).”

[Muslim, Book #001, Hadith#0158] “It is narrated on the authority of ‘Abdur-Rahman b. Abu Bakra that his father said: We were in the company of the Messenger of Allah (may peace be upon him) that he observed: Should I not inform you about the most grievous of the grave sins? (The Holy Prophet) repeated it three times, and then said: Associating anyone with Allah, disobedience to parents, false testimony or false utterance. The Holy Prophet was reclining, then he sat up, and he repeated it so many times that we wished that he should become silent.”

[Bukhari, Book #83, Hadith #9] “Narrated ‘Abdullah bin ‘Amr: The Prophet said, “Al-Kaba’ir (the biggest sins) are: To join others (as partners) in worship with Allah, to be undutiful to one’s parents,” or said, “to take a false oath.” (The sub-narrator, Shu’ba is not sure) Mu’adh said: Shu’ba said, “Al-kaba’ir (the biggest sins) are: (1) Joining others as partners in worship with Allah, (2) to take a false oath (3) and to be undutiful to one’s parents,” or said, “to murder (someone unlawfully).”

[Sunan Abudawud, Book #8, Hadith #1448] “Narrated Mu’adh al-Juhani: The Prophet (peace_be_upon_him) said: If anyone recites the Qur’an and acts according to its contents, on the Day of Judgment his parents will be given to wear a crown whose light is better than the light of the sun in the dwellings of this world if it were among you. So what do you think of him who acts according to his.”

[Sunan Abu Dawud, Book #41, Hadith #5123] “Narrated AbuUsayd Malik ibn Rabi’ah as-Sa’idi: While we were with the Apostle of Allah! (peace_be_upon_him) a man of Banu Salmah came to Him and said: Apostle of Allah is there any kindness left that I can do to my parents after their death? He replied: Yes, you can invoke blessings on them, forgiveness for them, carry out their final instructions after their death, join ties of relationship which are dependent on them, and honor their friends.”

Allah Hafiz.