ConfirmUserMail.php

<?php

// [...]

protected $user;

/**
 * Create a new message instance.
 *
 * @return void
 */
public function __construct($user)
{
    $this->user = $user;
}

/**
 * Build the message.
 *
 * @return $this
 */
public function build()
{
    return $this->view('emails.confirmation', [
        'token' => $this->user->confirmation_token,
        'id' => $this->user->id,
    ]);
}

// [...]