The World Federation One Stop Fiqh

Ruling 290

There is no problem if there is dirt under one’s nails. However, if the nails are clipped, in the event that the dirt is an obstruction for water to reach the skin, one must remove the dirt for the purposes of wuḍūʾ. Furthermore, if one’s nails are unusually long, then dirt collected under the length that is longer than normal must be removed.