Do clothes that touch a blanket containing an unspecified and not fully cleaned najis (impure) spot become najis, and does that prevent one from praying in them?

If the blanket is dry, impurity does not transfer from it to dry clothes that come into contact with it. However, if one of the two contacting items is wet, there is a difference of opinion regarding the transfer of impurity, and it is permissible to adopt the view that it does not transfer. To purify the blanket, the spot affected by urine should be washed by pouring water over it until it outweighs the impurity. It is not necessary to wash the entire blanket. If the location of the impurity is unknown, then one should wash what is certain to include the impure spot.