How to take a dump size more than 1024 using LLDB from iOS memory

I am trying to get decrypted binary from my iPhone 5s memory which is x64-bit, I saw couple of tutorials about GDB but unfortunately i cannot use it because i am on arm7 device, i have tried this solution but i get this errors:

(lldb) memory read --outfile /tmp/mem.bin --binary 0x1000 0x2000
error: Normally, 'memory read' will not read over 1024 bytes of data.
error: Please use --force to override this restriction just once.
error: or set target.max-memory-read-size if you will often need a larger limit.

When tried to use --force command i get this error:

(lldb) memory read --outfile /tmp/mem.bin --binary 0x1000 0x2000 --force
error: memory read failed for 0x1000

Then i tried to change the maximum read size but i got another error:

(lldb) set set max-memory-read-size 1000000
error: invalid value path 'max-memory-read-size'
(lldb) set append max-memory-read-size 1000000
error: invalid value path 'max-memory-read-size'

Is there any other way to do it, or maybe i am doing something wrong?