Sevenfold, i.e. either,
1. Abundantly, as this phrase notes, Isaiah 65:6,7 Jer 32:18 Luke 6:38. Or,
2. Sensibly, so as it may come home to them, and fall heavily upon them in their own persons. Reproached thee, as impotent, or unfaithful, or unmerciful to his own people. So they intimate that this desire did not proceed from a revengeful mind, but from a due sense of God's favour.