The Hebrew word kuttoneth (כֻּתֹּנֶת) refers to a long inner garment, tunic, or robe worn next to the skin. It is the most common garment word in the OT priestly and narrative texts, appearing about 29 times.
Kuttoneth marks pivotal moments in salvation history. God made kuttanoth of skin for Adam and Eve (Genesis 3:21) — the first act of redemptive covering after sin, requiring the death of an animal. Joseph's famous coat of many colors (Genesis 37:3) — his kuttoneth passim — triggered his brothers' envy and set in motion Israel's descent into Egypt. The priestly kuttoneth (Exodus 28:4, 39) was a finely woven linen garment worn by Aaron and his sons — holiness worn on the body. At the cross, soldiers divided Jesus' garments (cf. Psalm 22:18), and tradition associates his seamless garment with the high-priestly robe. The tunic thus threads from Eden's covering to the cross's atonement.