Jamieson, Fausset and Brown on Ezekiel 37:8

8. So far, they were only cohering in order as unsightly skeletons. The next step, that of covering them successively with sinews, skin, and flesh, gives them beauty; but still "no breath" of life in them. This may imply that Israel hereafter, as at the restoration from Babylon was the case in part, shall return to Judea unconverted at first (Zec 13:8, 9). Spiritually: a man may assume all the semblances of spiritual life, yet have none, and so be dead before God.