1. Surah Al-Isra (17:23)
۞ وَقَضَىٰ رَبُّكَ أَلَّا تَعْبُدُوٓا۟ إِلَّآ إِيَّاهُ وَبِٱلْوَٰلِدَيْنِ إِحْسَٰنًا ۚ إِمَّا يَبْلُغَنَّ عِندَكَ ٱلْكِبَرَ أَحَدُهُمَآ أَوْ كِلَاهُمَا فَلَا تَقُل لَّهُمَآ أُفٍّۢ وَلَا تَنْهَرْهُمَا وَقُل لَّهُمَا قَوْلًۭا كَرِيمًۭا
And your Lord has decreed that you not worship except Him, and to parents, good treatment. Whether one or both of them reach old age [while] with you, say not to them [so much as], "uff," and do not repel them but speak to them a noble word.
The command to worship Allah alone is followed at once by good treatment of parents, down to not saying 'uff' to them in their old age.
2. Surah Al-Isra (17:24)
وَٱخْفِضْ لَهُمَا جَنَاحَ ٱلذُّلِّ مِنَ ٱلرَّحْمَةِ وَقُل رَّبِّ ٱرْحَمْهُمَا كَمَا رَبَّيَانِى صَغِيرًۭا
And lower to them the wing of humility out of mercy and say, "My Lord, have mercy upon them as they brought me up [when I was] small."
The next verse continues: lower the wing of humility to them and pray, 'My Lord, have mercy upon them as they brought me up when I was small.'
3. Surah Luqman (31:14)
وَوَصَّيْنَا ٱلْإِنسَٰنَ بِوَٰلِدَيْهِ حَمَلَتْهُ أُمُّهُۥ وَهْنًا عَلَىٰ وَهْنٍۢ وَفِصَٰلُهُۥ فِى عَامَيْنِ أَنِ ٱشْكُرْ لِى وَلِوَٰلِدَيْكَ إِلَىَّ ٱلْمَصِيرُ
And We have enjoined upon man [care] for his parents. His mother carried him, [increasing her] in weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination.
Said in the passage of Luqman's advice to his son: the mother carried her child in weakness upon weakness, and gratitude to Allah is joined to gratitude to parents.
4. Surah Al-Ahqaf (46:15)
وَوَصَّيْنَا ٱلْإِنسَٰنَ بِوَٰلِدَيْهِ إِحْسَٰنًا ۖ حَمَلَتْهُ أُمُّهُۥ كُرْهًۭا وَوَضَعَتْهُ كُرْهًۭا ۖ وَحَمْلُهُۥ وَفِصَٰلُهُۥ ثَلَٰثُونَ شَهْرًا ۚ حَتَّىٰٓ إِذَا بَلَغَ أَشُدَّهُۥ وَبَلَغَ أَرْبَعِينَ سَنَةًۭ قَالَ رَبِّ أَوْزِعْنِىٓ أَنْ أَشْكُرَ نِعْمَتَكَ ٱلَّتِىٓ أَنْعَمْتَ عَلَىَّ وَعَلَىٰ وَٰلِدَىَّ وَأَنْ أَعْمَلَ صَٰلِحًۭا تَرْضَىٰهُ وَأَصْلِحْ لِى فِى ذُرِّيَّتِىٓ ۖ إِنِّى تُبْتُ إِلَيْكَ وَإِنِّى مِنَ ٱلْمُسْلِمِينَ
And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship, and his gestation and weaning [period] is thirty months. [He grows] until, when he reaches maturity and reaches [the age of] forty years, he says, "My Lord, enable me to be grateful for Your favor which You have bestowed upon me and upon my parents and to work righteousness of which You will approve and make righteous for me my offspring. Indeed, I have repented to You, and indeed, I am of the Muslims."
The verse names thirty months of carrying and weaning, then gives the prayer of a person who reaches forty: to be grateful for the favour on them and on their parents.
5. Surah An-Nisa (4:36)
۞ وَٱعْبُدُوا۟ ٱللَّهَ وَلَا تُشْرِكُوا۟ بِهِۦ شَيْـًۭٔا ۖ وَبِٱلْوَٰلِدَيْنِ إِحْسَٰنًۭا وَبِذِى ٱلْقُرْبَىٰ وَٱلْيَتَٰمَىٰ وَٱلْمَسَٰكِينِ وَٱلْجَارِ ذِى ٱلْقُرْبَىٰ وَٱلْجَارِ ٱلْجُنُبِ وَٱلصَّاحِبِ بِٱلْجَنۢبِ وَٱبْنِ ٱلسَّبِيلِ وَمَا مَلَكَتْ أَيْمَٰنُكُمْ ۗ إِنَّ ٱللَّهَ لَا يُحِبُّ مَن كَانَ مُخْتَالًۭا فَخُورًا
Worship Allah and associate nothing with Him, and to parents do good, and to relatives, orphans, the needy, the near neighbor, the neighbor farther away, the companion at your side, the traveler, and those whom your right hands possess. Indeed, Allah does not like those who are self-deluding and boastful.
A list of those owed good treatment begins with parents and continues to relatives, orphans, the needy, neighbours near and far, and the traveller.
6. Surah Al-Baqarah (2:83)
وَإِذْ أَخَذْنَا مِيثَٰقَ بَنِىٓ إِسْرَٰٓءِيلَ لَا تَعْبُدُونَ إِلَّا ٱللَّهَ وَبِٱلْوَٰلِدَيْنِ إِحْسَانًۭا وَذِى ٱلْقُرْبَىٰ وَٱلْيَتَٰمَىٰ وَٱلْمَسَٰكِينِ وَقُولُوا۟ لِلنَّاسِ حُسْنًۭا وَأَقِيمُوا۟ ٱلصَّلَوٰةَ وَءَاتُوا۟ ٱلزَّكَوٰةَ ثُمَّ تَوَلَّيْتُمْ إِلَّا قَلِيلًۭا مِّنكُمْ وَأَنتُم مُّعْرِضُونَ
And [recall] when We took the covenant from the Children of Israel, [enjoining upon them], "Do not worship except Allah; and to parents do good and to relatives, orphans, and the needy. And speak to people good [words] and establish prayer and give zakah." Then you turned away, except a few of you, and you were refusing.
The covenant taken from the Children of Israel: worship none but Allah, and do good to parents, relatives, orphans and the needy.
7. Surah Al-'Ankabut (29:8)
وَوَصَّيْنَا ٱلْإِنسَٰنَ بِوَٰلِدَيْهِ حُسْنًۭا ۖ وَإِن جَٰهَدَاكَ لِتُشْرِكَ بِى مَا لَيْسَ لَكَ بِهِۦ عِلْمٌۭ فَلَا تُطِعْهُمَآ ۚ إِلَىَّ مَرْجِعُكُمْ فَأُنَبِّئُكُم بِمَا كُنتُمْ تَعْمَلُونَ
And We have enjoined upon man goodness to parents. But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them. To Me is your return, and I will inform you about what you used to do.
Goodness to parents is enjoined, with one limit: if they push you to associate with Allah what you have no knowledge of, do not obey them.