The wave offering (tᵉnûpāh) is derived from a verb which means to move backwards and forwards. According to Ross (p.192), the offering was placed in the worshipper’s hands, and then the priest would place his hands beneath those of the worshipper. The offering would then be moved upward and downward, forward and backward, symbolizing its consecration in the sight of all.
30 Il apportera de ses propres mains ce qui doit être consumé par le feu devant l'Eternel; il apportera la graisse avec la poitrine, la poitrine pour l'agiter de côté et d'autre devant l'Eternel.