Speak thou also unto the children of Israel, saying, Verily my sabbaths ye shall keep: for it [is] a sign between me and you throughout your generations; that [ye] may know that I [am] the LORD that doth sanctify you.
Jewish Publication Society of America Version (JPS1917) - Exodus 31:13 >'Speak thou also unto the children of Israel, saying: Verily ye shall keep My sabbaths, for it is a sign between Me and you throughout your generations, that ye may know that I am the LORD who sanctify you.