Gershon dubin asks:
If rabbi Zakai's old mother had to sell her cap to buy him wine, where did have 300 barrels of wine to leave to him?
Gershon dubin , New York USA
The Kollel replies:
Sholom Rav.
The point the Gemara is making is that someone who is careful about Kidush over wine is rewarded with an abundance of wine, as Tosfos points out.
And that is what happened first, to R. Zakai's grandmother, and then to R. Zakai himself.
Be'Virchas Kol Tuv.
Eliezer Chrysler.