quick grep question

IIRC, the option is '-A <# of lines that follow>"
Example grep -A2 findthistext /opt/inthisfile

I would suggest something other than grep in this case.
If you know the the delimeter is definitely a single space, you may use cut, otherwise use awk.

Example input (t.t):

one two three four five six
one two three four five six
one two three four five six
one two three four five six
one two three four five six

Using cut:

$ cut -d' ' -f 3- t.t
three four five six 
three four five six 
three four five six 
three four five six 
three four five six 

Using awk:

$ awk '{ s = ""; for (i = 3; i <= NF; i++) s = s $i " "; print s }' t.t
three four five six 
three four five six 
three four five six 
three four five six 
three four five six