Repeatedly in the Book of Numbers, the Lord gives something to the people, escape from slavery, for example, and the people soon start complaining about not having one more thing. Often, their complaints seem understandable to me--when they are thirsty, they want water, but, overall, their complaints do demonstrate their limited trust in the Lord to provide everything they need.
Moses also complained. Earlier in chapter 11, he complained to the Lord about being burdened with all these complainers. The Lord responded by sharing the leadership responsibility with seventy elders.
As we today prepare for Pentecost Sunday, the remembrance of the Holy Spirit coming on the believers, we read this passage in Numbers about the Spirit coming down, speaking to Moses, and being shared with others. Those who received the Spirit were able to prophesy.
To the consternation of some, the Spirit also landed on a couple of men who had not been in the original group. When Joshua, Moses' assistant, tried to stop them from prophesying, Moses stopped him. Moses said, "Do you think I need to be the only one that hears what God says? Do you think I want God's attention on me alone?"
We continue to wrestle with the questions of who has the appropriate authority to speak in God's name and who should be in charge of this authorization.