Apparently urination was quite the common motif in ancient dreams.
From the Assyrian Dream Book, as relayed by some scholar:
If his urine [expands(?)] in front of (his) penis and [ ] the wall: [he will not have] sons.
If his urine ex[pands] in front of (his) penis and [ ] the wall, the street: he will h[ave] sons.
If his urine expands in front of his penis and f[ills(?) all] the streets: his property will be robb[ed] and given to the city [ ].
If his urine expands in front of (his) penis [and] he does obeisance in front of his urine: he will beget a son and he (i.e. the son) will be king....
If he sprinkles (himself) with his urine: his (sheep)-fold will expand.
If he sprinkles (himself) with his urine and wipes himself (clean): (the disease called) `Hand of Ishtar'.
If he directs urine towards the sky, the son of this man whom he will (thereafter) beget will become important, (but) his (own) days will be short.
If he pours his (urine) into a river: his harvest will be bountiful.
If he pours his urine into a well: he will lose his property.
If he pours his urine into an irrigation-canal: Adad will flood his harvest.
If he pou[rs] his urine to his (personal) god [or to] his (personal) goddess: he will [find(?)] his lost property.
The linked paper this is pulled from goes into an interesting discussion of Herodotus's mystic origin story of Cyrus the Great, founder of the first Persian empire. Like any good origin story, it includes a mother named "A bitch" and a father who unknowingly eats his son.