These verses highlight two prayer events at that time. The disciples pray, and then rise to minister to the people. What they do, is teach “those same words which Jesus had spoken.” For many, it was a refresher course, but there were many new people who had come in from the outlying areas for whom this was important new information.
Then, they pray again. Once again, there is the emphasis that they pray to the Father in the name of Jesus. The only reason for the frequent repetition of this fact is that it was new information that needed to be learned.