Keep my sabbaths: see verse 3.

Reverence my sanctuary: perhaps the sanctuary had been used in the practices forbidden in the previous verses. This says in a more positive way that proper respect was to be shown to the Israelite place of worship.

Quoted with permission from Péter-Contesse, René and Ellington, John. A Handbook on Leviticus. (UBS Helps for Translators). New York: UBS, 1990. For this and other handbooks for translators see here .