The fish raining down in this painting represents salvation, and divine abundant blessings.
This painting is referring to the story about the five loaves of bread and two fish.
Nothing is impossible! There are always miracles waiting for us in our lives.
Take a hold of them!

Matthew 14:17-20 
“We have only five loaves of bread and two fish,” they answered. “Bring them here to me,” he said. And he directed the people to sit down on the grass. Taking the five loaves and the two fish and looking up to heaven, he gave thanks and broke the loaves. Then he gave them to the disciples, and the disciples gave them to the people. They all ate and were satisfied, and the disciples picked up twelve basketfuls of broken pieces that were left over. The number of those who ate was about five thousand men, besides women and children.”