He memorised the Qur’an and forgot some verses of it; will he attain the reward of the one who memorised the Qur’an?

Firstly:

It is narrated concerning the virtue of the one who recites the Qur’an and acts in accordance with it that his father will be given a crown to wear on the Day of Resurrection. This has been explained previously in the answer to question no. 201387 .

Secondly:

In the answer to question no. 169485 , we explained that this virtue is attained by the one who memorises the Qur’an and not the one who simply reads it.

But if someone memorises the Qur’an and then forgets some verses of it, will his father be given that crown on the Day of Resurrection?

We do not know of any text regarding this issue, but the basic Islamic principles regarding reward and punishment indicate that one of two scenarios will apply to this person:

The first scenario is that his forgetting does not result from any negligence on his part; rather he was keen to retain what he had memorised, but he forgot it because of some reason or because of old age. In such cases, there is the hope that he will have reward and will attain the virtue of the one who memorised the Qur’an, because he put great effort into pursuing this virtue until he attained it, and whatever he forgot he did not forget it deliberately, and Allah, may He be glorified and exalted, says (interpretation of the meaning):

{Indeed, those who have believed and done righteous deeds – indeed, We will not allow to be lost the reward of any who did well in deeds} [al-Kahf 18:30].

But if his forgetting resulted from heedlessness and negligence on his part, and he did not care and stopped reciting Qur’an, then what appears to be the case is that this is a type of nullifying good deeds, and backsliding after having advanced. In this case, he may miss out on the virtue of having memorised the Qur’an, because the text that encourages memorising the Qur’an speaks of persisting in it, so the Muslim would recite the Qur’an regularly and act in accordance with it, not to memorise it once then neglect it. Hence it is stipulated in the hadith that one should act in accordance with it and not forsake it.

Abu Daawood (1453) narrated from Sahl ibn Mu‘aadh al-Juhani, from his father, that the Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever recites the Qur’an and acts in accordance with what it contains, his parents will be given two crowns to wear on the Day of Resurrection…”

And Allah knows best.