The phrase "分一杯羹" is formed by directly combining the character 分 (to divide), the measure phrase 一杯 (one cup), and the noun 羹 (thick soup), resulting in the literal meaning "to divide a cup of soup". It originates from a specific historical account where Liu Bang, in a confrontation with Xiang Yu, stated that if his father were boiled in a soup, he would want a share of it, thus solidifying the phrase as an idiom that metaphorically expresses taking a portion of benefits or profits.