Create a nested form : "undefined method `push'"

I would like to build a new Review form, but it return me an error than I don't understand. Con you explain me the problem ?

My code

routes :

resources :posts do 
    resources :pushs do 
      resources :reviews
    end 
  end 

The link :

<%= link_to 'Add comment', new_post_push_review_path(@push.post_id, @push) %>

The form that I would like to built :

<%= simple_form_for([@post, @post.push.reviews.build]) do |f| %>

<%= f.input :rating %>
<%= f.input :comment %>
<%= f.button :submit %>

<% end %>

& finally, the controller review :

class ReviewsController < ApplicationController
  before_action :authenticate_user!
  before_action :find_push
  before_action :find_post




  def new 
    @review = Review.new 
    @pushs = Push.all
  end 

  def create
    @push = Push.find(params[:review][:id])
    @review = Review.new(review_params)

     @review.post_id = @push.post_id
     @review.push_id = @push.id 
     @review.user_id = current_user.id

    if @review.save 
      redirect_to push_path(@push.post_id, @push)
    else 
      render 'new'
    end 
  end 

private 

  def review_params
    params.require(:review).permit(:rating, :comment)
  end 



   def find_post
    @post = Post.find(params[:post_id])
  end 

  def find_push
    @post = Post.find(params[:post_id])
    @push = @post.pushs.find(params[:push_id]) 
  end 

end

Well, if you have any ideas to explain me my error(s), that would be great !!