'The clean beast' means, as previously, affections for good. 'The beast that is not clean' means evil desires. 'Bird' in general means thoughts. 'Everything that creeps over the ground' means the sensory part and every associated delight. 'Two and two' means complementary things. 'They went into the ark' means that they were protected. 'Male and female', as previously, means truth and good. 'As God had commanded Noah' means that it was so accomplished.