He answered, “Do not tell them, lest they come to rely on it.” Muʿādh only reported this ḥadīth when he was on his deathbed, fearing that concealing such knowledge would be sinful. Agreed upon.

His phrase “fearing sin” means: out of fear that withholding this knowledge would itself be a sin.

[Explanation]
After the author (may Allah have mercy on him) set out the chapter on fear, he followed it with the chapter on hope. It is as though he intends to give precedence to fear, or to say: when you notice that fear has overtaken you, then open the door of hope.

The author then quoted verses and ḥadīths, among them the words of Allah the Exalted: “Say, My servants who have transgressed against their own souls, do not despair of Allah’s mercy. Indeed, Allah forgives all sins; He is the All-Forgiving, the Most Merciful” (al-Zumar 53).

This verse was revealed about those who repent: if a person repents, Allah turns to him in acceptance, no matter how grave his sin—just as He, the Most High, also says: “Those who do not call on any other god together with Allah, who do not kill a soul that Allah has made sacred—except with legal right—and who do not commit adultery. Whoever does that shall meet a penalty. The punishment will be doubled for him on the Day of Resurrection, and he will abide therein humiliated—except for those who repent, believe, and do righteous deeds; for such Allah will replace their evil deeds with good, and Allah is ever Forgiving, Merciful” (al-Furqān 68–70).

So whoever repents of any sin, Allah accepts his repentance no matter how enormous the sin. However, if the sin involves the rights of other created beings, then their rights must be restored