When a person dies, his deeds come to an end except for three things: ongoing charity, beneficial knowledge, or a pious child who supplicates for him

Benefits from the hadith

1. The scholars unanimously agreed that the rewards that reach a person after his death include ongoing charity, beneficial knowledge, supplication, and Hajj, as mentioned in other Hadīths.
2. He singled out these three things in the Hadīth because they represent the foundations of goodness and they are mostly the things virtuous people want to endure after their passing.
3. Any beneficial knowledge will bring reward, but at the top and pinnacle of it is the Shar‘i knowledge and the sciences that support it.
4. Knowledge is the most beneficial of these three, because knowledge benefits the person who learns it, preserves the Shariah, and benefits people in general. Plus, it is more comprehensive and inclusive as people learn from your knowledge that exists during your lifetime and endures after your death.
5. The Hadīth encourages us to raise righteous children, as they are the ones who will benefit their parents in the Hereafter, and an example of their benefit is that they supplicate for them.
6. It encourages kindness to parents after their death, which is also a form of righteousness from which the child benefits.
7. Supplication benefits a deceased person even if the supplicant is not his child. But, a person's child is specifically mentioned because he is mostly the one who continues to supplicate for his parents until he dies.