the minor’s affairs solely in his best interests: he may build any houses he owns of clay and fired bricks, but not of unfired brick or plaster; nor may he sell the child’s real estate except out of necessity or for an obvious, demonstrable gain. He is permitted, when advantageous, to sell the ward’s property by barter or on deferred terms; if he does sell on credit, he must summon witnesses and secure the price with a pledge. He may claim or waive the right of pre-emption on the child’s behalf according to what best serves the benefit. He must pay zakat on the minor’s wealth and support him in a manner customarily recognized as fair. If, after reaching puberty, the ward alleges against his father or grandfather that they sold his property without benefit, those two are believed upon taking an oath; but if he levels the same charge against an executor or trustee, the ward himself is believed on his own oath.