Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...Nf6/6. Qe2/6...d5/7. Nxf6/7...gxf6/8. d4/8...Bg7

9. dxe5 is consistent with the plan of attacking the e-pawn several times and then capturing it.