The rebbe explains that also by the benoni there are two levels as by the tsaddik: 1: one who works on himself for G-d, 2: one who does not work on himself. Because the one who works on himself has desires, and the one who does not work on himself has no desires, since naturally he is a cool person. And therefore he does not have to think a lot in order not to sin, and he does not need a great love to g-d as by praying in order not to sin, rather it is enough for him with the natural love which every Jew has in his heart. And therefore he is called 'one who does not work' since all he does is natural. And so is it by someone which trained himself to learn at all times, it is not hard for him to not stop learning. And therefore he is called 'one who does not work' since the learning became a part of him and now it is natural.