Keren Kayemeth is Hebrew for the Jewish National Fund, the land purchase and development fund of the Zionist Organization. It was founded on December 29, 1901 at the Fifth Zionist Congress at Basle, which resolved: "The JNF shall be the eternal possession of the Jewish people. Its funds shall not be used except for the purchase of lands in Palestine and Syria." The Hebrew name comes from the talmudic dictum about good deeds "the fruits of which a man enjoys in this world, while the capital abides (ha-keren kayyemet) for him in the world to come" (Pe'ah 1:1). A land fund was first suggested by Judah Alkalai in 1847. It was proposed by Hermann Schapira at the *Katowice Conference in 1884 and again at the First Zionist Congress in 1897. Schapira based his idea of public ownership of land on the biblical injunction "The land shall not be sold forever for the land is Mine," and on the institution of the Jubilee Year, which stipulates that all holdings which have changed hands revert to their original owners in the 50th year (Lev. 25:10, 23–24).

JNF leasehold contracts run for 49 years and can be prolonged by the lessee or his heirs as long as they serve the purpose specified; holdings may neither be united with other domains nor divided among several heirs; the lessee needs the lessor's consent if he wishes to use his holding for a purpose other than that stipulated in the contract; on rural tracts, the lessee must cultivate his own soil; ground rents are to be kept as low as possible, whether the land serves farming, industry, housing, or other purposes.