Commandment of treating parents well has been mentioned in the Holy Quran and blessed Ahadees: In verse 23 and 24 of Surah Bani Israel part 15 Allah Almighty has stated:

وَ قَضٰى رَبُّكَ اَلَّا تَعْبُدُوْۤا اِلَّاۤ اِیَّاهُ وَ بِالْوَالِدَیْنِ اِحْسَانًاؕ-اِمَّا یَبْلُغَنَّ عِنْدَكَ الْكِبَرَ اَحَدُهُمَاۤ اَوْ كِلٰهُمَا فَلَا تَقُلْ لَّهُمَاۤ اُفٍّ وَّ لَا تَنْهَرْهُمَا وَ قُلْ لَّهُمَا قَوْلًا كَرِیْمًا(۲۳)

Translation from Kanz-ul-Iman: And your Lord has commanded that do not worship anyone except Him, and treat parents with goodness; if one of them or both reach old age in front of you, so do not say (even) ‘Ugh’ to them and do not scold them, and speak to them words of respect. And spread for them the arm of humbleness with a soft heart, and request humbly that, ‘O my Lord! Have mercy on them both, just as they brought me up in my childhood.’

(Part 15, Surah Bani Israel, Ayah 23 -24)

Regarding these blessed verses Allamah Maulana Sayyid Mufti Muhammad Na’eemuddin Muradabadi رَحْمَةُ اللهِ عَلَيْه has said: When parents become weak, their body parts do not have power and they become as weak in their last days as you were with them in your childhood, do not say any such thing which shows that they are burden on you. Neither scold them nor speak loudly to them but rather talk to them in a very respectful manner as a slave or servant talks to his master. Treat them gently and humbly and treat them with affection and love when they feel bored because they brought you up with love when you were helpless and do not become stingy in spending what they need. It means no matter how greatly you treat and look after them in the world, but you cannot fulfil the rights of their favours. A bondman, therefore, should make Du’a to Allah Almighty to have blessing and mercy on them and should humbly say: O my Lord! My services cannot be the return for their favours; You have mercy on them so that it can be the return for their favour.

صَلُّوۡا عَلَى الۡحَبِيۡب           صَلَّى اللّٰهُ عَلٰى مُحَمَّد