Is it permissible for the guardian of his brother's heirs to take his travel expenses and the like from the heirs' money without their knowledge, due to customs, knowing that he is in debt?

Devouring the orphan's wealth unjustly is one of the seven destructive sins. Islamic law obligates the guardian to preserve the orphan's wealth, develop it, and pay its Zakat. If the guardian is wealthy, he should abstain from taking anything from it; if he is poor, he may partake of it in a reasonable manner; and if he is an agent managing their wealth, he is entitled to a customary wage. Allah Almighty says: (And whoever is rich, let him abstain [from taking anything from it]; and whoever is poor, let him partake thereof in a reasonable manner). The poor person may eat according to his need or his customary wage, whichever is less, and he is not required to return what he has eaten if he later becomes affluent. It is not permissible to take a wage for visiting orphans. However, what is spent on them from clothing, food, and the like should be from their own wealth. It is advisable to consult the Sharia court regarding such matters and to reflect on the Hadith: "Whoever seeks to abstain, Allah will make him abstain; whoever seeks self-sufficiency, Allah will make him self-sufficient; and whoever seeks patience, Allah will make him patient."