The Japanese General is giving out white rice to any Chinese person who defeats the Japanese fighters at a ratio of 1 bag per 1 defeated fighter.
The General kills Ip Man's friend in a 1(General)vs 3(Chinese men) duel. Right before the scene shown in this video, Ip Man witnesses Sifu Liu getting shot to death by the Colonel for losing a duel with 3 Japanese fighters and still dare to pick up the bag of rice he won earlier, though not by the orders of the General. Ip Man gets real pissed off, so he demands a fight with 10 of the black belts. Upon his victory, he refuses to take his reward(10 bags of rice) and the General tells him "again"; Ip Man replies "I did not come here for the rice". The interpreter tells the General that he will come again. The General asks for his name and Ip Man replies "I am just a Chinese". The interpreter tells the General, "He is Ip Man".
Mandarin Dubbed + Original Japanese Speech