Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.9)
// Compass (v1.0.1)
// ----

  // Delete the "" in productive use
  
  $icons: (
      pencil-square-o : "$fa-var-pencil-square-o",
      user : "$fa-var-user",
      key : "$fa-var-key",
      shopping-cart : "$fa-var-shopping-cart",
      life-ring : "$fa-var-life-ring",
      angle-left : "$fa-var-angle-left"
  );

  @each $icon-key in map-keys($icons) {
    $icon-value: map-get($icons, $icon-key);
    li.#{$icon-key} a:before {
      content: $icon-value;
    }
  }

SassMeister-output.css

li.pencil-square-o a:before {
  content: "$fa-var-pencil-square-o";
}

li.user a:before {
  content: "$fa-var-user";
}

li.key a:before {
  content: "$fa-var-key";
}

li.shopping-cart a:before {
  content: "$fa-var-shopping-cart";
}

li.life-ring a:before {
  content: "$fa-var-life-ring";
}

li.angle-left a:before {
  content: "$fa-var-angle-left";
}