The word "Dhamma" in this phrase can also be translated as little d "dhamma", signifying phenomenon. However, the way it is worded in this translation (whose translation is it?) has been rendered in such a way that it precludes the (little d) "dhamma" interpretation.
I believe this is referring to non-becoming, particularly applied during meditation practice. We should let go of fine-states of becoming, to say nothing of the coarser states.
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
Having understood name-and-form, which is a product of prolificity,
And which is the root of all malady within and without,
He is released from bondage to the root of all maladies,
That Such-like-one is truly known as 'the one who has understood'. (Snp 3.6)