After seeing this tweet I looked for an early account of this attempt to destroy the pyramids during the era of the crusades. It turns up in the writings of a contemporary, ʿAbd al-Laṭīf al-Baghdādī (1162-1231), in his Kitāb al-Ifādah wa-l-iʿtibār, which recounts his travels ...
... in Egypt as well as observations on its flora, fauna, monuments, etc. He dedicates a substantial section to the pyramids of Egypt. ʿAbd al-Laṭīf rightly notes that Gizah houses many pyramids of varying sizes, not merely the famous “big 3”. 
He notes that Ṣalāh al-Dīn (Saladin) already ordered many of the smaller pyramids in Gizah destroyed, as he needed stone for his massive building program in 1176-77, aimed at constructing bridges and walls around Cairo and Fusṭāṭ. The destruction was overseen by Qarāqūsh ...
a Roman eunuch. When Saladin's son, al-ʿAzīz ʿUthmān, took over Egypt for his father, ʿAbd al-Laṭīf claims that he was seduced by fools from his entourage who convinced him to destroy the three great pyramids in 1197...
He started with the smallest, known today as the pyramid of Menkaure (left), and by that time the pyramid was already over three millennia old. ʿAbd al-Laṭīf marveled that had been constructed from red granite ...
Stonemasons, sappers, cavalry, infantry were all summoned – using levers and pushing stones from above and pulling stones with fastened ropes and ties from below and hardly moving a stone or two per day for 8 months. One can still see the damage to the face of the pyramid today.
ʿAbd al-Laṭīf bemoans all of this as a pathetic waste of time, effort, and money. He ends his account by recounting how he asked the foreman of the stonemasons, “If someone gave you 1000 dinars to return a single stone to its place and position, could you do that?”
“I swear by God Almighty,” the foreman replied, “they would not be able to do that even if you offered them many times that!”
Source:
ia902500.us.archive.org/7/items/rhlt-a…
Source:
ia902500.us.archive.org/7/items/rhlt-a…
See also on the pyramids and pharoanic Egypt in the medieval Islamic period:
jstor.org/stable/1595483
and
jstor.org/stable/27801602
and
academia.edu/8494464/al-Mam…
jstor.org/stable/1595483
and
jstor.org/stable/27801602
and
academia.edu/8494464/al-Mam…
And I nearly forgot!ʿAbd al-Laṭīf al-Baghdād also wrote a wonderful autobiography which has been translated into English. (It famously contains some rather interesting comments about Maimonides.) See here:
google.com/books/edition/…
google.com/books/edition/…
