This may be simpe but cant seem to get it working. I have the following submit button
<%= f.submit \'Send Message\', class: \'btn submit\', id: \'validFor
Use button_tag and put the span within the button in that way
<%= button_tag(type: 'submit', class: "btn submit", id: 'validForm') do %> <span class="icon-envelope"></span> Send Message <% end %>