It is a lovely post from you. Although I am hesitant to accept the ' historical reasons of revelations' (Shan-e-Nuzool), it might be true in this case.
You said: "He responded to them by reciting the first 13 verses of Surah Fussilat, until they asked him to stop. (Al-Hakim and Al-Bayhaqi)"
Please rethink your use of PBUH. See my next post about PBUH from Dr. Shabbir's "Islam: The True History And False Beliefs".
Here are those beautiful 13 verses from Surah Fussilat nicely expounded in QXP.
Surah 41. Fussilat – A Book Clearly Spelled Out
[Author’s Note] This is the 41st Surah of the Qur’an. It has 54 verses narrating the impact of belief and disbelief in the individual and collective lives of the human beings. The Surah concludes with a powerful announcements that all people on the face of the earth will eventually recognize that this Qur’an is the Final Word of God and it solves all the problems that mankind does and ever will face.
Some historians have called this Surah, ‘Ha-Mim AS-Sajdah’. QXP (The Qur’an As It Explains Itself) once again, would stick to the original unanimity. Additionally, in this particular case, Fussilat is not only a simpler and highly expressive term, but furthermore avoids getting this Surah mixed up with
Surah 32, As-Sajdah, in the reader’s mind.
With the Glorious Name of God, the Instant and Sustaining Source of all Mercy and Kindness
41:1 H.M. Ha-Meem (Hakeem the Wise, Majeed the Glorious, states that),
41:2 This is a revelation from the Beneficent, the Merciful.
41:3 A scripture whose verses are clearly explained in detail, a Lecture in Arabic, for people who would learn. [7:158, 12:3, 13:37, 14:4, 25:1, 39:28, 42:7]
41:4 Good news and a warning. Yet, most of them turn away so that they do not hear.
41:5 And so they say, "Our hearts are veiled from what you invite us to, and (consider) there is deafness in our ears, and that between us and you is a barrier. So, do as you will, and we do as we will.”
41:6 (O Prophet) say to them, "I am only a human being like you. It has been revealed to me that your God is one and the same; the One and only God. So, take the straight path to Him and seek His forgiveness. There is great loss for those who choose gods besides God, [Mushrikeen = = Idolaters = Those who worship their own desires. Wayl = Woe = Ultimate loss = Destruction]
41:7 Those who do not contribute toward Zakaat and even deny the Hereafter.”
[Disbelieving the Law of Just Recompense equals denying the Eternal life. Zakaat = The Just Economic Order. Aakhirah = Life to come = Life Hereafter = Future = The Ultimate Abode]
41:8 But those who accept the Divine revelation and contribute toward improvement of the society, shall have a reward unending.
41:9 Say, "What! Do you deny Him Who has created the earth in Two Eras? And would you still ascribe rivals to Him? He is the One, the Sustainer of the worlds." [36:40, 79:30. Yaumayn = Two days = Two stages = Two Eras = Two Aeons = Indefinitely long periods]
41:10 And He is the One Who placed therein firm mountains towering above it, and bestowed enduring bliss upon it. And He measured therein its sustenance in Four Eras, alike for all who (invariably) need it.
[39:67, 56:63-73. Six Eras or Stages: 41:9 Says ‘Two Eras', 41:12 says ‘Two Eras’. Thus, according to the Qur’an, the creation of the heavens and earth took place in Two Eras. The word Yaum here means a very long period. (A thousand years of your reckoning (32:5) or it may be fifty thousand years (70:4). In scientific terms, the period of creation of the material world is called 'Azoic' or Lifeless. The Qur’an however, divides this period into two and calls it Two Eras. Modern scientific research throws some light on the division of Azoic Era into two: To begin with, the entire space was full of smoke (41:11). Smoke, as we know, is a mixture of gases and solid particles. Areas of condensation appeared later in this gas and the dust cloud, resulting in the formation of Prostars which further developed into stars. The stars further became divided into planets and other smaller heavenly bodies. The division of one complete whole of Smoke to Prostars is a great event. Thus we may call the period before the division of the whole Smoke as Era-I of the creation of the Universe; and the period after this division until the appearance of life as Era-II. The Qur’an divides the time of creation after the appearance of life on the earth into Four Eras. Two plus Four makes 'Six Eras' of evolution. 32:4]
41:11 Likewise, He is the One Who designed well the Sky when it was Smoke (Nebulae of gas). And He said to it and the earth, "Come both of you willingly or unwillingly." They said, "We do come, obedient." [Thumm = Afterward, then, so, likewise, similarly, in the like manner. The Cosmic bodies coming into their orbits willingly or unwillingly indicates their being inherently subservient to Divine laws, unlike humans who have been granted free will. 3:82, 13:15]
41:12 And He is the One Who ordained that they become seven heavens in Two Eras and assigned to each heaven its function. And We decorated the sky of the world with shining lamps, and made them secure (that they do not clash in their orbits 41:9). That is the Design of the Almighty, the Knower.
41:13 But if they turn away, then tell them, "I warn you of a thunder like the thunder of ‘Aad and Thamud.”