Genesis 4:22

4:22 Now Zillah also gave birth to Tubal-Cain, who heated metal and shaped all kinds of tools made of bronze and iron. The sister of Tubal-Cain was Naamah.

Genesis 49:15

49:15 When he sees a good resting place,

and the pleasant land,

he will bend his shoulder to the burden

and become a slave laborer.