Is it permissible to pray in clothes that have been stained by the urine of a three-month-old baby, knowing that he consumes yogurt, milk, and some other foods?

The urine of a child is impure by consensus, whether male or female, except for the dissenting opinion of Dawud al-Zahiri. The purification of a boy's urine differs from that of a girl's; a girl's urine is washed, whereas for a boy's urine, it is sufficient to sprinkle water (nadh), which means splashing water over the area of the urine without it flowing. This distinction is established in the Sunnah and is the view of the Shafi'is and Hanbalis, contrary to the Hanafis and Malikis who mandated washing for both. The boy for whom sprinkling suffices is one who has not yet eaten solid food; once he has eaten food, his urine must be washed like a girl's urine. A nursing mother is excused from washing a baby's urine and feces if she strives to prevent harm and some of it gets on her due to hardship.