Is it permissible to let young children pray with the congregation while they are in a state of ritual impurity?

If a child is discerning (mumayyiz), he is to be commanded to pray, and his prayer is valid, provided it meets the conditions for the validity of an adult's prayer. Guardians must command him to purify himself for prayer and discipline him for abandoning it once he reaches the age of ten. As for those who are below the age of discernment, they are not commanded to pray. It is permissible for them to stand in the rows with adults, but their prayer is not valid. Their guardians must ensure they are clean to prevent soiling the mosque.