The following hadith is from the companion Abu Hurairah ra, the Prophet Muhammad pbuh said: "When a person dies, his deeds are cut off except for three things: continuous charity, beneficial knowledge, and a righteous child who prays for him." (HR. Bukhari and Muslim) Through the above hadith, the existence of a righteous child has a very positive impact on both parents. Wherever righteous deeds are performed by a righteous child, the parents will also receive rewards. Here is a more detailed explanation of why the prayer of a righteous child becomes an ongoing reward for both parents after their death, as summarized by Dream through various sources.

It is also explained by Allah SWT in the holy verses of the Quran that rewards in the afterlife are obtained from deeds done in the world. As stated in Surah Al-Baqarah verse 202: "They are the ones who will have a share of what they have earned, and Allah is swift in account." (Quran, Al-Baqarah: 202) Now, children are part of the parents' efforts in raising them to become righteous individuals. The Prophet Muhammad (peace be upon him) said: "The best provision is that which you earn through your own efforts. And indeed, your children are part of your efforts." (Hadith, Tirmidhi)

In this case, the prayer of a righteous child for both parents shows that the prayer and righteous deeds performed by a child will also bring rewards and benefits to the parents. In Islamic teachings, it is explained that the good deeds performed by a child will bring rewards to the parents, even if the child does not verbally pray for them. Just like when someone leaves a perpetual charity, they will receive rewards even if the beneficiary does not pray for the giver.

That's why Islam strongly encourages its followers to pay full attention to their children's education. The goal is for the child to become a righteous individual. As a result, the child not only respects their parents but also every good deed they perform can bring rewards to their parents, even after their parents have passed away. A righteous child will surely understand the significance of the prayers they offer for their parents. These prayers are especially meaningful, especially when the parents have already passed away. In fact, the prayers of a righteous child can help their parents or provide relief for them, even if the parents do not have good deeds.