1)
From where did they obtain wine?
1.
Rashi (to 19:33): They were about to conceive two nations that HaSh-m intended to inhabit the world, so He prepared wine for them in the cave to bring His plan to fruition. 1
1
Gur Aryeh (to 19:33): Why explain in this way? The verse writes "ba'Lailah Hu," rather than the usual "ba'Lailah ha'Hu." The "Hu" alludes to HaSh-m; it was He Who supplied the wine.