Bede

And they fasted for seven days. Literally and rightly for the dead, so that they may reach rest, it is fasted for seven days, which after the six ages of this world, in which we labor in the flesh, the seventh is in that world the age of rest for the souls freed from the flesh, in which the blessed await that glorious time when they may deserve to rise. The figure of this rest and resurrection, and the seventh day in the law, and the seventh or fiftieth year, in which rest of works was given, typologically foretold. …

Commentary on Samuel ↗