Our experience of time is highly subjective; it depends on our individual brain or self. But time also has an objective facet, a measurable facet, that we can capture or demonstrate in the ticking of a metronome or a clock, which continue on, in the same way, even when we sleep.
We lose touch with this objective facet of the world much of the time, not least when we sleep. Yet not even in deep dreamless sleep, do we lose our being. It is always closer to reality than the objective ticking of the clock or the metronome. It is only the part of us that is in the world of the clock or metronome that needs promises or covenants, which are all about time. In deep dreamless sleep we are free of that world, and all is already said and done.