Why does the stop sign (لا) differ among Qur'anic manuscripts after the word "malaa'ikah" (angels), and after the word "eemaanan" (faith), and after the word "wal-mu'minoon" (and the believers) in Surat Al-Muddaththir?

The letter "لا" (la) in the Mushaf indicates a prohibited stop (waqf mamnu'), meaning "do not stop here." This is because the word is connected to what follows it in a way that prevents stopping, either to avoid misunderstanding the intended meaning or to prevent conveying the opposite meaning. Judging a word as having a prohibited stop is a matter of ijtihad (independent reasoning). Some scholars mentioned that stopping at "المَلاَئِكَةُ" (the angels) in the aforementioned verse from Surat Al-Muddaththir is permissible (hasan), while stopping at anything else is prohibited.