A few offerings are waved (moved upward, downward, back, and forth) as a part of the process of offering them. If I'm not mistaken, the following is a complete list:
- The asham of the m'tzora, while it's still alive, along with the oil he brings.
- The fats destined for the mizbeach, and the chaze v'shok (breast and leg), of an individual's sh'lamim.
- The kivse Atzeres (sheep brought specially on Shavuos), while alive, along with the bread brought with them.
- The kivse Atzeres's fats destined for the mizbeach.
- The omer.
- The mincha of a sota.
Why these specifically? What's special about these korbanos (and bikurim) that has to do with waving?
Note that I'm not asking how we know these are waved: in each case, there's a pasuk from which we derive the halacha. Rather, I'm asking why God commanded that these be waved.