King James Version (KJV)
It shall devour the strength of his skin: even the firstborn of death shall devour his strength.
Modern English
It consumes the parts of his skin; the firstborn of death consumes his limbs.
Hebrew
יֹ֣אכַל בַּדֵּ֣י עוֹר֑וֹ יֹ֝אכַ֗ל בַּדָּ֥יו בְּכֽוֹר מָֽוֶת׃
yoʾkal badey ʿvorvo yoʾkal badayv bkvor mavet