Proper way to pass values

Assuming that we have the following class, is it better (in terms of oop) to pass the object of class Foo to Bar constructor rather than pass only the arguments baz and qux to Bar constructor?

class Foo
{
    public $baz, $qux;

    public function __construct($baz, $qux)
    {
        $this->baz = $baz;
        $this->qux = $qux;
    }

    public function main()
    {
        $bar = new Bar($this);
        //OR
        $bar = new Bar($this->baz, $this->qux);
    }
}