The term came into widespread use within the Yishuv, or Jewish population of Palestine, in the 1930s, but is thought to have been used as far back as the early 20th century, when it was used to refer to the first generation of native-born Jews produced by the Zionist movement, the children of the immigrants of the First Aliyah. This generation of natives referred to themselves as "etrogim." The term "Tzabar" may have been used by immigrants of the Second Aliyah and the Third Aliyah, originally as an insulting term. The changing of the meaning of the term, to emphasize the softer interior rather than the roughness, was done by the journalist Uri Kesari, who himself was a sabra. Kesari published an essay, "We Are the Leaves of the Sabra!", on 18 April 1931 in the newspaper Doar HaYom in which he argued against the discrimination which was cast against the native-born by the new immigrants. The 1931 census of Palestine found that of a recorded Jewish population of 174,610, 73,195 people (42%) were born in Palestine.