The literal sense first, the reading in brackets
When a word's literal sense and a reading drawn from context coexist, the translation keeps the literal and carries the reading in square brackets. The reading is kept only if other passages of the Qur'an support it.
Sura 89 swears "By the even [the state in which intercession is permitted], and the odd [the state in which it is refused]!" (89:3). The text says "the even" and "the odd"; the translation keeps them. The reading in brackets comes from the root of the word "even" (شفع), which is also that of intercession, and from two passages: "Who, then, intercedes with Him, except with His permission?" (2:255); "So there will not benefit them the intercession of any intercessors." (74:48).
Sura 86 describes the fluid from which the human being is created, "emerging from between the loins [of the man] and the bosom [of the woman]" (86:7). The brackets specify to whom each word belongs; the word "loins" is the Qur'an's own word for descent: "your sons from your own loins" (4:23).
In sura 68, the companion of the fish "called out while suppressing [his sorrow]" (68:48). The bracketed complement rests on the account of Yaqub, where the same word goes with sorrow: "while he suppressed his sorrow" (12:84).
The reader can thus read the text without the brackets, then with them, and judge the proposed reading.
In the text
وَٱلشَّفْعِ وَٱلْوَتْرِيَخْرُجُ مِنۢ بَيْنِ ٱلصُّلْبِ وَٱلتَّرَآئِبِإِذْ نَادَىٰ وَهُوَ مَكْظُومٌۭ