In religious and historical texts, he is lauded as the deity who opens up the subterranean sources in order to irrigate the fields.

He heaps up the grain in the storehouses, and on the other hand, the withdrawal of his favor is followed by famine and distress.

Jensen[130] would conclude from this that he was originally (like Marduk, therefore) a solar deity.
This, however, is hardly justified, since it is just as reasonable to deduce his role as the producer of fertility from his powers as lord of some body of water.

However this may be, in the case of Nabu, there are no grounds for supposing that he represents the combination of two originally distinct deities.

A later--chiefly theoretical--amalgamation of Nabu with a god Nusku will be discussed in a subsequent chapter.[131] Hammurabi and his immediate successors, it is noteworthy, do not make mention of Nabu.