Is it permissible for a Muslim who has memorized the Qur’an to make that known in order to encourage others, or is it better to keep it a secret between himself and his Lord?

It is permissible for a person to speak about the knowledge or memorization that Allah has blessed him with if it is to ward off harm from himself, or to bring benefit to people, such as encouraging them to seek knowledge. This is not considered the forbidden self-praise, for Allah Almighty said through the words of Yusuf (peace be upon him): (He said, "Appoint me over the treasuries of the land. Indeed, I am a knowledgeable guardian.") Ibn Mas'ud (may Allah be pleased with him) did likewise. Al-Nawawi mentioned that self-praise is permissible when there is a need, such as warding off evil, achieving a benefit for people, or encouraging the acquisition of knowledge. As for the prohibition of self-praise, it applies to those who do it for boastfulness and self-admiration. However, whenever a person can conceal his deed, it is better, so that he does not fall into boastfulness and self-admiration.