output neighbouring lines with line numbers while grepping

Is there a way to output the neighbouring lines along with the line numbers while grepping the contents of a file? I'm trying to get outputs of the form:

$ ~/myscript.sh download file # 'download' being the pattern here
121: # and downloads with wget/curl, whichever is available.
122: download_file () {
123:  if which wget &>/dev/null; then
----------
356: # Since the prerequisites are already installed, we may proceed
357: download_urls=("http://ift.tt/1xvYt6A"
358:                "http://ift.tt/1xvYtmQ"

Of course, I know that I can get grep my pattern with the -n option and show some of the neighbouring lines from the obtained line number (say, by using any of the methods here), but is there a better way to do this?