Deuteronomy 16:11-12

16:11 You shall rejoice before him – you, your son, your daughter, your male and female slaves, the Levites in your villages, the resident foreigners, the orphans, and the widows among you – in the place where the Lord chooses to locate his name. 16:12 Furthermore, remember that you were a slave in Egypt, and so be careful to observe these statutes.