Rashi on Leviticus 3:1/רש"י על ויקרא ג׳:א׳

1שלמים PEACE-OFFERINGS — They are so called because they bring peace (שלום) into the world. Another explanation is: they are called שלמים because through them there is “peace” (harmony and lack of envy) to the altar, to the priests and to the owners (since all these receive a portion) (cf. Rashi on Exodus 29:22 and our Note thereon; see also Sifra, Vayikra Dibbura d'Nedavah, Chapter 16 2).