Scroll of Natural Acceleration

Suspend 1--{1}{g} (Instead of playing this card from
your hand, exile it with 1 time counter on it for {1}{g}. At the beginning of your upkeep, remove a
time counter from it. If there are no time counters on
it, you may cast it without paying its mana cost.)
Sacrifice Scroll of Natural Acceleration: Add {g}{g}{g}. Until end of turn, green mana doesn't
empty from your mana pool as steps and phases
end.