What is the ruling regarding the purity of the inner part of clothing? Is it sufficient to purify only the outer part due to difficulty and hardship, and to avoid combining prayers for someone whose clothes are repeatedly contaminated by children's urine?

Previous fatwas have clarified rulings regarding the purity of an infant and how to cleanse the urine of a boy and a girl. They mentioned that the Malikis pardon minor impurities from an infant, provided effort is made to remove them. As for delaying prayers and gathering them all at the end of the day, that is a grave sin, because performing prayer outside its prescribed time without a valid excuse is among the major sins. The utmost allowance for a woman who finds it difficult to change her clothes is to combine Dhuhr and Asr, and Maghrib and Isha, during the time of one of them, as permitted by the Hanbalis. However, it is preferable to be diligent in performing prayers at their prescribed times. If an outer or inner garment becomes impure, it must be purified or replaced with a pure garment before prayer, because avoiding impurity is a condition for the validity of prayer. When in doubt about the presence of impurity, the default assumption is the continuation of purity.