As for the prophetic reports the author cited, one of them is the ḥadīth of ʿAbdullāh ibn ʿAmr ibn al-ʿĀṣ: the Messenger of Allah ﷺ said, “O ʿAbdullāh, do not be like so-and-so; he used to rise for the night prayer, then he abandoned the night prayer.”

The term fulān is a conventional way of referring to an unnamed person; for a woman one says fulāna. It is possible that this wording came directly from the Prophet ﷺ, who withheld the man’s name from ʿAbdullāh ibn ʿAmr in order to protect him, for the lesson concerns the deed, not the doer. It is also possible that the Prophet ﷺ actually named the man, but ʿAbdullāh ibn ʿAmr chose to leave him unidentified. In either case, what matters is the substance of the teaching.

The point is that a man used to stand in prayer during the night but failed to keep it up. Although the night prayer is, in principle, a sunnah practice—had he never performed it, no one would have reproached him or asked, “Why did you not rise for the night prayer?”—once a person adopts it and then abandons it, he becomes blameworthy. For that reason the Messenger ﷺ warned, “Do not be like so-and-so; he used to stand for the night prayer, then he abandoned the night prayer.”

An even graver example is the one who sets out to seek sacred knowledge and, after Allah opens the way for him, turns away from it. This is ingratitude for a blessing Allah has bestowed. Therefore, if you have begun the pursuit of knowledge, persevere—unless something of absolute necessity prevents you. Otherwise, remain constant, for the pursuit of knowledge is an obligation.