Deuteronomy 15:18

15:18 You should not consider it difficult to let him go free, for he will have served you for six years, twice the time of a hired worker; the Lord your God will bless you in everything you do.

Deuteronomy 23:4

23:4 for they did not meet you with food and water on the way as you came from Egypt, and furthermore, they hired Balaam son of Beor of Pethor in Aram Naharaim to curse you.