sharkskin scabbard
A scabbard covered in sharkskin or ray skin, historically used for Japanese swords. This is a specialized historical term.
その刀は鮫鞘に収められていた。
The sword was sheathed in a sharkskin scabbard.
Compound of 鮫 (same, 'shark') and 鞘 (saya, 'scabbard'). The reading ざや is a rendaku form of さや.