Paul employs both in 1 Cor 11,33 and in Rm 2,10 the metaphor of 'depth' (bathos) associated with the theme of knowledge. In the two units (1 Corinthians 1–4; Romans 9–11), this metaphor is related to other terms: 'mystery', 'wisdom', 'mind of the Lord' (Is 40,13 in 1 Cor 2,16 and Rm 11,34). After outlining the semantic nuances of the metaphor, we study its inventio (why does Paul use it?), and then reflect on how the two passages combine the limitation of human knowledge, the greatness of divine revelation, and the promise of eschatological salvation.