gistfile1.php

<?php

class Person extends Eloquent
{
    protected $table = 'people';
}

class ReadOnlyPerson extends Person
{
    public function save()
    {
        throw new \Exception('You cannot save a read only model!'); // or no-op and just return true/false
    }
}

$person = Person::find(1);
$person->firstName = 'David';
$person->save(); // OK

$person = ReadOnlyPerson::find(1); // Eloquent queries will still work
$person->firstName = 'David';
$person->save(); // throws exception

// OR

class Person extends Eloquent
{
    protected $table = 'people';

    public function save()
    {
        if ($this->someProperty == 'someValue') {
            throw new \Exception('You cannot save this model!'); // or no-op and just return true/false
        }

        return parent::save();
    }
}