John Gill Commentary Mark 13:2

"And Jesus said unto him, Seest thou these great buildings? there shall not be left here one stone upon another, which shall not be thrown down." — Mark 13:2 (ASV)

And Jesus answering said to him
The Persic version reads, "to them"; and so Beza's most ancient copy but as that question is put by one, the reply is made to him:

Do you see these great buildings ?
how beautiful and strong they are. The Vulgate Latin and Ethiopic versions, add the word all; and the sense is, Do you take a survey of all these buildings, and of the whole of this stately edifice? And do you not admire the strength and grandeur of them? And do you not think they will be of long duration, and that the demolition of them is scarcely possible?

There shall not be left one stone upon another .
The Syriac and Arabic versions add, "here": as in (Matthew 24:9) , and so it is read in four of Beza's copies, and in others:

that shall not be thrown down; (See Gill on Matthew 24:2).