Lest thou shouldest ponder - To prevent thee from reflecting on thy present conduct, and its consequences, her ways are moveable - she continually varies her allurements.
Thou canst not know them - It is impossible to conceive all her tricks and wiles: to learn these in all their varieties, is a part of the science first taught in that infernal trade.
Or (with the Septuagint and Vulgate), Lest she should ponder (or “She ponders not”) the way of life, her paths move to and fro (unsteady as an earthquake); she knows not. The words describe with a terrible vividness the state of heart and soul which prostitution brings upon its victims; the reckless blindness that will not think, tottering on the abyss, yet loud in its defiant mirth, ignoring the dreadful future.