It does not spare nor leave anything.
Translation endnotes
[74:28] The Quran does not want us to rush into defining the meaning of the word saqar, since it introduced it with a question followed up by an explanation. Past generations understood it as another word for Hell. After the discovery of the role of 19 in the Quran and fulfillment of the prophecies in this chapter and in other verses of the Quran, now we know that Saqar refers to an intellectual punishment. The extreme allergy and aversion demonstrated by Sunni and Shiite mushriks against the number 19 is part of the prophetic fulfillment of these verses.