Does the impurity of drops of urine that exit after urinating and sleeping transfer to the bedding through sweat, thus making it impure, or is it among what is excused?

Underwear that has become impure with dry urine will transfer its impurity to outer garments and bedding that come into contact with sweat, provided that contact is confirmed. If there is doubt about the transfer, then impurity is not decreed. Moreover, it is well-known among most فقهاء (jurists) that a small amount of urine is not excused unless it is difficult to guard against it.