We find that in the Wisdom literature the chief object of the divine omniscience is man, the human race in general and its deeds and thoughts, its actions and meditations. On the other hand, divine omniscience appears in the Wisdom literature as more complete than in the Psalms. In the latter, indeed, it does not reach the world of the dead, but stops, so to speak, at the threshold of the lower regions. Yahweh, more or less of choice, knows nothing of the dead:
Raffaele Pettazzoni, The All Knowing God, p 102