If one uses a tissue after istinjah to prevent urine drops going onto his underwear but forgets to remove it and does wudhu and prays, then will the prayer be valid? Assuming that the urine is less than a dirham on the tissue.
In the name of Allah, the most Beneficent, the most Merciful.
If there is a sign or mark of the impurity on your underwear it will be necessary to wash it off before commencing the salah. The urine of human beings is considered as a Najaasat Ghaleeza (heavy type of impurity) and washing is wajib if the impurity covers an area greater than the size of a dirham. If it is less than a dirham, then the salah performed in this manner will be discharged. This does not mean one should leave minor impurities on one’s clothes, as to perform salah without washing even the minimum allowed limit is makruh. (Nurul Idaah p.51 –p.54 & p.88)
Regarding your question, if the urine was less than a dirham, the salah will be valid but disliked and if it was more than the size of a dirham, the salah will be considered invalid.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham.