Here are the verses from chapter 74.

11. Leave Me to him whom I created alone.

12. And gave him vast wealth.

13. And children as witnesses.

14. And smoothed things for him.

15. Then he wants Me to add yet more!

16. By no means! He was stubborn towards Our revelations.

17. I will exhaust him increasingly.

18. He thought and analyzed.

19. May he perish, how he analyzed.

20. Again: may he perish, how he analyzed.

21. Then he looked.

22. Then he frowned and whined.

23. Then he turned back and was proud.

24. And said, “This is nothing but magic from the past.

25. This is nothing but the word of a mortal.”

26. I will roast him in Saqar.

27. But what will explain to you what Saqar is?

28. It neither leaves, nor spares.

29. It scorches the flesh.

30. Over it are Nineteen.

31. We have appointed only angels to be wardens of the Fire, and caused their number to be a stumbling block for those who disbelieve; so that those given the Scripture may attain certainty; and those who believe may increase in faith; and those given the Scripture and the believers may not doubt; and those in whose hearts is sickness and the unbelievers may say, “What did Allah intend by this parable?” Thus Allah leads astray whom He wills, and guides whom He wills. None knows the soldiers of your Lord except He. This is nothing but a reminder for the mortals.

The verse in question is no 30 Over it are Nineteen. Early books of tafsir has resolved the pronoun it in this verse to refer to Saqar or hellfire mentioned earlier in verse 26. It means that there are 19 angels guarding Saqar (or Hellfire). When this verse was revealed, the infidels (like Abu Jahl) said, ‘look at Muhammad! the hellfire has only 19 angels and we the tribe of Quraish are so many in number that we can easily overcome those gurads and escape hellfire’, and so on they kept on mocking this number. That is why in verse 31 Allah mentioned that this number became a cause of doubt and stumbling block for the disbelievers. Little known to these mockers that the soldiers of Allah are so many in number that no one knows their actual number.

I have tried tafsirs: Ibn Jarir at-Tabari, Ibn Kathir, Al-Baghawi, Ibn Al-Jawji and all of them referred to 19 as the guards of Hellfire. Al-Mawardi in his tafsir of “al-Nukat wal Oyoun” alluded to the possibility that 19 is a number that Allah made to preserve this universe with 7 planets and 12 constellations.

Al-tha’alebi in Jawaher al-Hisan said that “there is no difference in opinion among scholars that this 19 refers to the heads of the guards of Hellfire”.

Al-Aloosy in his tafsir (Ruh al-Ma’ani) after citing the famous opinion of 19 being the main guards of Hellfire, started to cite some other opinions that signify the number 19. Among them is the 12 types of human souls inner and outer animal drives (e.g., the anger, the intellect, the animal, etc.) and the 7 natural drives (e.g., attraction, repel, etc.) totaling to 19. Another opinion is that the day is 24 hours, and five of them goes for five prayers, which does not need an angel, but the remaining 19 hours need an angel for each of them. After citing these weak opinions, the author (al-Aloosy) said, ‘all such opinions if one carefully scrutinizes them knows that they are no reliable and sound opinions, and Allah guides those He wills to the right path.’

Al-Aloosy actually took these opinions from al-Razi (who is the scholar inclined the most towards investigating such hidden meanings) in his tafsir book “Mafateeh al-Ghaib”.

As you can see none of these early scholars applied 19 to the Quran. The majority used it to be the elders of the guards of Hellfire (i.e., Saqar), and a minority made a passing mention of other possibilities, but none of these possibilities included 19 to apply on the Quran.

Among the explanations some tafsir authors mentioned (e.g., Al-Beqayee in his book Nadhm ad-Durar) said that 9 is the max of unit numbers and 10 is the min of tens, so 19 combines the max of min, and the min of max. He also mentioned that Ibn Masood said that the Bismillahi rRahman arRaheem is 19 letters and each saves from one of the 19 guards of Hellfire.

So applying the referent of the pronoun it in this verse 74:30 to the Quran is not what the early scholars understood from this verse. The Arabic pronoun Aliha meaning ‘Over it’ is referring to a feminine entity which goes very well with Saqar being a feminine entity, and never to the Quran which is a masculine entity and should have been used the pronoun Alihi instead of Aliha. Similarly, the end of verse 31 is This is nothing but a reminder for the mortals. Here again the pronoun This hiya is feminine referring to the Saqar, and not the Quran for which the pronoun should have been huwa.

Given the above, Rashad Khalifa and all those created a huge research thread on 19 might have started from wrong premises and created a huge enterprise on unwarranted hypothesis.

Having said that, I understand that the Quran is an amazing book, and I do believe it has miraculous wonders in all aspects, its styles, and rhetorics and is full of still undiscovered hidden gems. Computational means is a power that should be used to explore the Quran in an attempt to unearth such hidden treasures. The researcher should be open to any number and not necessarily on the number 19.

Taking the entire story of this chapter no. 74 from verse 11 to 31 has a strong linkage with the Quran. Remember that this man called al-Walid Ibn al-Mughira to whom all these verses are referring was a scholar of language and knows the Arabic Poetry system very well. When he first heard the Quran, he became amazed and saw a unique wonderful language system that is superior to the best of the poetry he came across in his life and started to think and think and think more about this Quran, and finally, he decided to call the Quran a Magic. So, overall, the context of these verses indeed is about the awesomeness of this Quran.