A kehillah is different from the other two kinds of community. Its members are different from one another. In that sense it is like a tzibbur. But they are orchestrated together for a collective undertaking – one that involves in making a distinctive contribution. The danger of a kehillah is that it can become a mass, a rabble, a crowd.
That is the meaning of the phrase in which Moses, descending the mountain, sees the people dancing around the calf:
Moses saw that the people were running wild, and that Aaron had let them get out of control and so become a laughing-stock to their enemies (32: 25).
The beauty of a kehillah, however, is that when it is driven by constructive purpose, it gathers together the distinct and separate contributions of many individuals, so that each can say, “I helped to make this.” That is why, assembling the people on this occasion, Moses emphasizes that each has something different to give: Take from what you have, an offering to G-d. Everyone who is willing to bring to G-d an offering of gold, silver and bronze…. All you who are skilled among you are to come and make everything the Lord has commanded….
Moses was able to turn the kehillah with its diversity into an edah with its singleness of purpose, while preserving the diversity of the gifts they brought to G-d:
Then the whole Israelite community withdrew from Moses’ presence, and everyone who was willing and whose heart moved him came and brought an offering to G-d for the work on the Tent of Meeting, for all its service, and for the sacred garments. All who were willing – men and women – came and brought gold jewelry of all kinds: brooches, earrings, rings and ornaments…. Everyone who had blue, purple or scarlet yarn…. Those presenting an offering of silver or bronze…. Every skilled woman spun with her hands and brought what she had spun…. The leaders brought onyx stones and other gems…. All the Israelite men and women who were willing brought to G-d freewill offerings for all the work G-d, through Moses, had commanded them to do (35:20-29).
The greatness of the Tabernacle was that it was a collective achievement – one in which not everyone did the same thing. Each gave a different thing. Each contribution was valued – and therefore each participant felt valued. Vayakhel – Moses’ ability to forge out of the dissolution of the people a new and genuine kehillah – was one of his greatest achievements.
Many years later, Moses, according to the sages, returned to the theme. Knowing that his career as a leader was drawing to an end, he prayed to G-d to appoint a successor: “May G-d, Lord of the spirits of all flesh, appoint a man over the community” (Bamidbar 27:16). Rashi, following the sages, explains the unusual phrase “Lord of the spirits of all flesh” as follows:
He said to Him: Lord of the universe, the character of each person is revealed and known to You – and You know that each is different. Therefore appoint for them a leader who is able to bear with each person as his or her temperament requires (Rashi on Bemidbar 27:16).
To preserve the diversity of a tzibbur with the unity of purpose of an edah – that is the challenge of kehillah-formation, community-building, itself the greatest task of a great leader.