This is a Meccan surah, said to have been revealed after Sūrat al-Shams and before Sūrat al-Tīn.
As it is a Meccan surah, it was revealed at a time when the Muslims were under intense pressure and facing brutal persecution. God reminds them that there were those who persecuted believers by digging trenches filled with fire and burning them alive, yet those believers stood firmly in their faith and their persecutors all eventually perished. The main theme is hence related to persecution and is a reminder to the oppressors that their wickedness will not go unanswered, and to the believers that they should stand firm and not let persecution cause them to abandon faith.
It is mentioned in reports that when the Prophet read Sūrat al-Burūj he would seek refuge with God from the severity of tribulations.
The previous surah speaks of how everything is created with a purpose of returning to its Creator, O man! You are labouring toward your Lord laboriously, and you will encounter Him (84:6). To return to Him in a state other than submission is to return to doom and calamity. This surah continues with that line of thought, emphasising how those who oppress the believers will face eventual destruction in this world and doom in the hereafter. The same inevitability of return to God is emphasised here as well, It is indeed He who originates and brings back again (verse 13).
The previous surah spoke of how the disbelievers hide enmity towards God, His religion, and the believers in their hearts, And Allah knows best what they keep to themselves (84:23), so this surah continues from that, describing how that enmity has resulted in wicked persecution of believers, only because they had faith in Allah (verse 8).
[1] Tibyan, 10/315; Thalabi, 10/164.
[2] Tantawi, 15/341.
[3] See Razi, 31/106; Nemuneh, 26/324.
[4] See also Tantawi, 15/341.
[5] See for example Tabrisi, 10/706; Nur, 5/547; Razi, 31/110.
[6] See also Muhit, 10/442.