The use of brackets in books and the distinction between the words of the Messenger and the words of the narrator

The questioner:
You mentioned a hadith: “Whoever is able to do so, let him do it.” Why does the author use the small brackets? That is, the end of the hadith of the Messenger (peace and blessings be upon him). The second bracket—what is the relationship between what comes before and what comes after? The author, a little before, quotes Abu Hurayrah: “Whoever is able to do so, let him do it.” Perhaps it is a mistake. You mentioned that this is a narration. Why did the author not place the small brackets at the end of the hadith’s narration and use the specific ones to indicate the relationship between what precedes it and the others?

The Shaykh:
The authors do not place brackets. Brackets only came with the printing presses. There were no brackets before, but... Yes, all of this is a defect that must be [addressed].

The questioner:
The intention is merely [to clarify].

The Shaykh:
It is not necessary. There are those who hold that “whoever is able to do so” is from the words of the Messenger, and there are those who hold that it is from the words of the narrator. Yes, but even if it is implied to be from the words of the narrator, it is not necessary to separate them, because the scholars distinguish between the words of the Messenger and the words of others, even if they are not separated. Yes. Praise be to Allah.