Impurity (filth) نجاسة

(Whoever sees) in a dream that there is impurity on him, and he holds a deposit, a trust or testimony, or owes a debt or the like, which it would be a sin for him not to render: if he washes off that impurity, he will acquit himself of it by returning his trust. If he did not perform ablution but cleaned himself and washed the impurity, he will be free of sin while the debt remains on him; he will strive to meet his need and pay his debt and his trust, or return his deposit, and the debt and the trust will remain with him without sin.

[Chapter of the letter Ha.]