Ruby on Rails: New post not saving on the blog

I'm working on an exercise, creating a blog with ruby on rails. I have the form ready to post an article, but once I click on the submit button, I am redirected to the homepage but the article doesn't save. Here is the following code

class ArticlesController < ApplicationController
  def index
    @articles = Article.paginate(:page => params[:page], per_page: 5).order('created_at DESC')
  end

  def show
    @article = Article.find(params[:id])
  end

  def new
    @article = Article.new
  end

  def create
    @article = Article.new(title: params.permit[:title], body: params.permit[:body])

    if @article.save
      redirect_to articles, :notice => "Your post has been saved"
    else
      render :create
    end
  end

end

Here is the view create.html.haml

.container
    .row
        .col-xs-9-
            .panel-title
                %h2 Ecrivez votre article
                = form_for @article do |f|
                    = f.text_field :title
                    = f.text_area :body, size: "60x12"
                    = f.submit "Publier"

Then the route.rb, I don't know if it can help

TP2::Application.routes.draw do
  resources :articles, only: [:index]

  get 'articles' => 'articles#index'

  get 'articles/:id' => 'articles#show'

  get 'articles/new'

  get 'post' => 'articles#create'

  post 'articles' => 'articles#index'

And to finish here is what the console show when I try to post an article

Started GET "/post" for 127.0.0.1 at 2016-04-10 14:24:56 +0200
Processing by ArticlesController#create as HTML
   (0.2ms)  BEGIN
   (0.2ms)  ROLLBACK
  Rendered articles/create.html.haml within layouts/application (1.4ms)
Completed 200 OK in 9ms (Views: 4.9ms | ActiveRecord: 0.4ms)


Started POST "/articles" for 127.0.0.1 at 2016-04-10 14:25:10 +0200
Processing by ArticlesController#index as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"FMQmKvZ1t98ZE21VaiBQhm0jKJ9x9BwkXFbh4obfi3Qea0Zax5dgGirfpgcAiQA464GMD2+Qv/eGYrmvEoTZBQ==", "article"=>{"title"=>"Post", "body"=>"New Article test"}, "commit"=>"Publier"}
  Article Load (0.6ms)  SELECT  "articles".* FROM "articles"  ORDER BY created_at DESC LIMIT 5 OFFSET 0
   (0.4ms)  SELECT COUNT(*) FROM "articles"
  Rendered articles/index.html.haml within layouts/application (3.4ms)
Completed 200 OK in 7ms (Views: 5.3ms | ActiveRecord: 1.0ms)

I don't understand why the new article won't save. Does anyone understand why ?