Like this?

  $ cat << EOF > ~/.commit_reasons; strfile ~/.commit_reasons
  Testing...
  %
  Testify...
  %
  Testarossa...
  %
  Does it work yet?
  %
  How bout now?
  %
  Oops.
  %
  Fixed a thing.
  %
  EOF
  
  $ fortune ~/.commit_reasons | cowsay | git -F -