Thanks everyone for your replies. I am happy now with the explanation that it is an idiomatic thing to do with Pali. I can accept Ven. Thanissaro and Ven. Bodhi's explanations, they cover it adequately.
Then the Blessed One, picking up a tiny bit of dust with the tip of his fingernail, said to the monk, "There isn't even this much form...feeling...
perception...fabrications...consciousness that is constant, lasting, eternal, not subject to change, that will stay just as it is as long as eternity."