A.T. Robertson Commentary Hebrews 4:9

"There remaineth therefore a sabbath rest for the people of God." — Hebrews 4:9 (ASV)

A sabbath rest (σαββατισμος). Late word from σαββατιζω (Exodus 16:30) to keep the Sabbath, apparently coined by the author (a doubtful passage in Plutarch). Here it is parallel with καταπαυσις (cf. Revelation 14:13).

For the people of God (τω λαω του θεου). Dative case of blessed personal interest to the true Israel (Galatians 6:16).