Allah s.w.t. says in the Quran:
وَوَصَّينَا الإِنسانَ بِوالِدَيهِ إِحسانًا
“We have commanded people to honour their parents.”
(Surah Al-Ahqaaf, 46:15)
Our parents have sacrificed a lot to raise us and we will never be able to repay them. Other than treating them kindly, one of the best things we can do is to constantly make sincere dua for them.
رَبَّنَا اغفِر لي وَلِوالِدَيَّ وَلِلمُؤمِنينَ يَومَ يَقومُ الحِسابُ
Rabbana ighfir lee waliwalidayya walilmumineena yawma yaqoomu alhisab
"Our Lord! Forgive me, my parents, and the believers on the Day when the judgment will come to pass."
(Surah Ibrahim, 14:41)
وَقُل رَبِّ ارحَمهُما كَما رَبَّياني صَغيرًا
Rabbi irhamhuma kama rabbayanee sagheera
“My Lord! Be merciful to them as they raised me when I was young.”
(Surah Al-Isra’ 17:24)