In Luke 10:1-24, Jesus appointed seventy (or seventy-two, depending on the manuscript tradition) disciples and sent them ahead of him in pairs to every town and place he intended to visit. This mission is distinct from the earlier sending of the Twelve apostles (Luke 9:1-6).
The number seventy carries symbolic significance rooted in Genesis 10, which lists seventy nations descended from Noah's sons. In Jewish tradition, seventy represented the total number of Gentile nations in the world. By sending out seventy disciples, Jesus signalled that his message was not limited to Israel alone but was intended for the Gentiles - all the nations of the earth.
By contrast, the mission of the Twelve symbolised the mission to Israel, corresponding to the twelve tribes. The seventy thus broadened the scope of the gospel message beyond Jewish boundaries. Judea was a single region, not the universal scope indicated by the number. The mission of the Seventy specifically prefigured the later expansion of the gospel to the Gentile world, which the book of Acts records in detail.