Commentary Par XXIX 19-21

Two major issues are touched on here.  If our sense of the history of the world begins with Creation (i.e., Genesis 1:1), what was God doing before then?  (Attributed to St. Augustine is the retort, 'preparing a Hell for the inquisitive' [see DDP Carroll.Par.XXIX.19-30].)  Dante's point is that whatever He was doing, He was not lazing about, even if there was, strictly speaking, no time before the Creation.

The second problem is of a different order.  What exactly does 'God moved upon these waters' mean?  Precisely what 'waters' are referred to?  The obvious reference is to Genesis 1:2.  The first commentator (but hardly the last) to point to the work of Bruno Nardi was Porena (DDP Porena.Par.XXIX.19-21).  Nardi had shown (see Nard.1944.1), pp. 307-13, that one traditional medieval interpretation of this biblical text was that these waters are above the rest of the heavens (the Primum Mobile was also referred to as the 'acqueous sphere').  As Bosco/Reggio (DDP Bosco.Par.XXIX.19-21) point out, Dante's use of the demonstrative adjective 'queste' (these) makes that solution even more attractive, since Dante and Beatrice are currently in the Primum Mobile.