Isaiah 56:6

56:6 As for foreigners who become followers of the Lord and serve him,

who love the name of the Lord and want to be his servants –

all who observe the Sabbath and do not defile it,

and who are faithful to my covenant –

Isaiah 58:13

58:13 You must observe the Sabbath

rather than doing anything you please on my holy day.

You must look forward to the Sabbath

and treat the Lord’s holy day with respect.

You must treat it with respect by refraining from your normal activities,

and by refraining from your selfish pursuits and from making business deals.