File Photo: Israeli army spokesman Rear Admiral Daniel Hagari. AFP
The material taken from dead or captured Palestinians shows detailed plans for an assault that aimed to cause "such a shock as to break people's spirit", one officer told reporters.
Data from mobile phones, computers, tablets, GPS devices, GoPro cameras, maps, and notebooks "show years of planning on how to attack bases and kibbutzim," claimed another intelligence officer, both speaking on condition of anonymity.
To analyze the material, Israel has reactivated a military intelligence unit called Amshat to plow through the numerous Arabic documents and decipher millions of pieces of electronic data.
Together, they constitute "a battle plan," one officer said. "The level of detail and readiness are the biggest surprise."
The claims has not been verified from independant sources.
The Amshat unit was founded after the 1973 Arab-Israeli war when Israel was blindsided by Egyptian and Syrian attacks to liberate Sinai and has been reactivated several times since.
The New York Times reported on December 1 that more than a year ago Israeli intelligence had obtained a Hamas plan giving step-by-step details of an attack similar to October 7, but which was judged to be an "imaginary" scenario.
Captive-taking manual
Detailed tactical plans were discovered on computers, including objectives, names of the units involved and missions assigned to each of them, together with precise operational details, timings and a list of weapons needed.
There was a detailed hand drawing of the military outpost of Nahal Oz, which Hamas seized.
On the bodies of dead resistance fighters were found satellite photos and precise plans of two of the attacked Israeli illegal settlements.
One intelligence officer said he was sure that settlement details came from the inside, from either Palestinian workers or Arab Israelis.
"For the base, we don't know," the officer said. "But it cannot be by open source."
The media briefing was also told that "part of the training was on how to take hostages" and that "checklists" and "phrase books" had been found.
The checklist seen by AFP tells militants to cover their eyes and tie the hands of all adult captives.
It adds that the captive-takers should "kill those who cause problems or seek to escape".
A conversation guide shown to AFP includes around 50 expressions in Hebrew transcribed phonetically, including "shut up", "don't move", "hands in the air" and "lie down".
'Gold nugget'
Some documents found were unrelated to the October 7 operation, including several deemed to be of high military value.
"Some of the Hamas fighters were kept in the dark and did not know what would happen," said one officer.
"A lot of them came with things that were not relevant to the raid, some with cars used on a daily basis," said the other.
In the mountain of information, one intelligence officer said, "Some things were known, some are new ... We have to find the gold nugget".
One officer said that a detailed map of southern Gaza had been found, identifying previously unknown Hamas installations.
Journalists were also told that Amshat had obtained allegedly images of tunnels in Gaza, without being told how these were obtained.
The presumed images showed long corridors, reinforced by concrete and metal, wide and high enough for a vehicle to pass through.
One intelligence officer said they would "not be surprised" if there were more than 500 kilometers (300 miles) of deep, interlacing tunnels in total.
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