cat(1) -n Foremost_All%2Faudit.txt %7C grep -i -A 20 %22Files Extracted%22
concatenate files and print on the standard output
-n, --number
       number all output lines
Concatenate FILE(s), or standard input, to standard output.

With no FILE, or when FILE is -, read standard input.
-A, --show-all
       equivalent to -vET
source manpages: cat