David's speech to the assembly of princes (1 Chronicles 29:1-9) has a roughly chiastic form. It begins with David's review of his contributions to the temple and his declaration of his delight in God's house. He sets an example by donating additional gold and silver and calls on the people to “fill their hands” by giving generously. The assembly donates huge amounts of metals and stones, then responds with stunned joy at their own generosity. The section ends with David rejoicing along with his people.
David radiates joy for the temple. The assembly catches the infection, and the joy returns to David. David exults, the assembly rejoices, and we end with the climactic joy of king and people.
A. David gifts to and delight in Elohim's house, vv 1-3
B. David gives more, vv 4-5a (natan, “give”)
C. Who is willing to fill the hand? v 5b
C'. Princes are willing, v 6
B'. Princes give, vv 7-8 (natan, 2x)
A'. Joy of assembly and king, v 9
The word for “willing” (nadav), often bearing the sense of “free-will offering,” runs through the speech. It is used four times in verses 1-9, seven in the entire chapter. Who is “willing” to give? David asks (v. 5). The princes offer willingly (v. 6) and then rejoice at the scope of their free will offering (v. 9). Their hearts are shalem (v. 9), complete or whole with Yahweh, as David hopes Solomon's will be (cf. 28:9), their devotion evident in their willingness to give. David's willingness to give is as infectious as his delight, and the two are related: Joy takes the concrete form of open-handed generosity, and, in a neat chiasm of joy, opened-handed generosity increases joy.
We may tease out two more abstract conclusions. First, joy is a social emotion. It is shared, and in being shared, in being given and returned, it intensifies and includes others within the compass of delight. We might even say that joy is an economic emotion, expressed in our distribution of goods and services to God and neighbor. Joy overflows, not only as emotion but as generosity, above all in generous giving to the project of building God's house. God loves a cheerful giver.
Second, joy is a fruit of the Spirit (Galatians 5), and so the dynamics of joy express the dynamism of the Spirit. Joy is infectious because the Spirit is given and received, because the Spirit flows out of the belly of those who receive Him (John 7). And the Spirit is given and received concretely in acts of joyous generosity. Christians form a communion (koinonia) because we have things in common (koinon), because we have a Person in common, the Spirit of Jesus and the Father. That communion has invisible mystic dimensions, but it is not merely mystical and invisible. The Spirit's presence is marked by shared joy, visible in generous sharing of goods for the edification of God's temple.