万马奔腾 (萬馬奔騰）is a famous Chinese proverb, means "Ten Thousand horses gallop forward".
Explanation for the characters in the artwork from top to bottom.
1,
Small seal script of character Ten Thousand, which is a scorpion with many feet. Experts believe that there were too many scorpions in the ancient time, so use it to be a big number.
2, 
Small seal script of character Horse
3,
The top is a person who is running, the bottom are three feet. Why three not two? Because when something is moving very fast, you could not see it clearly, such as the steel bars on bicycle wheels, you only see the blur of them. Ancient Chinese use three feet to represent the person is running too fast to see his feet clearly.
4,
Big seal script of character Soar.
The left is a boat, the right top is fire (torch), the middle are two hands holding the torch, the bottom is a horse. Actually, the boat + torch + hands form a character of King, who is riding a horse gallops ahead, leading a big army forward.
