This is an image of Swedenborg's handwritten inscription on a printed copy of his book The Brief Exposition. The Latin "Hic Liber est Adventus Domini" has been variously translated as "This book is the coming of the Lord", "This book is an advent of the Lord" or even "This book concerns the Lord's coming." "Scriptum ex mandato" means "Written by command" (BTW, Swedenborg's use of capitalization may or may not be significant). The remainder of the inscriptionciting 2513, 4535, 6895, 8427 (All from Arcana Coelestia I presume; I have no idea what the ".p.19" appended to the last one signifies) and AR 626 (from Apocalypse Revealed)appears to comprise references to other of his works (click on the links to read them).
Swedenborg himself wrote about this inscription, "When Brief Exposition was published the angelic heaven, from east to west and from south to north, appeared purple colored with the loveliest flowers; this happened before my very eyes and before those of the kings of Denmark, and others; on another occasion it appeared as if it were on fire, and beautiful.
"'The Coming of the Lord' was written on all the books in the spiritual world; by command I therefore wrote this in the same place in two copies in Holland."
The above image is from the one of those two copies that has been found.
In April 2014 my sister Lisa, who is a professional translator of Swedenborg's works, had this to say:
Your discussion says that you have no idea what the p. 19 after 8427 means. Here's the answer. Swedenborg didn't have subsection numbers, of course, and 8427 is two pages long in the first edition, so the page number helps narrow it down. I suspect the part he's talking about is this: ""The disciples said to Jesus, 'Tell us what the sign of your coming will be.' Jesus said, 'Then will appear the sign of the Son of Humankind, and they will see the Son of Humankind coming in the clouds of the sky with strength and glory'" (Matthew 24:3, 30).This is about the final period of the previous church and the first period of a new church. The Son of Humankind is divine truth coming from the Lord. The clouds of the sky are the Word in its literal meaning. The strength and glory are the inner meaning—and consequently divine truth—that will appear at that time. The Lord's coming stands for an acknowledgment of divine truth by people in the new church and a denial of it by people in the old church; see §4060 at the end.
She also sent two pages from a copy of the first edition showing the original Latin from which she quotes above: