Is a mother entitled to dispose of her son's money without his knowledge, and is the son's objection to her disposing of his money considered a wrongful act towards her? And how can a son regulate and purify his intention for the sake of Allah Almighty in bearing his family's expenses, and overcome the whispers of Satan that make him doubt his sincerity?

It is permissible for parents to take from their child's wealth what they need, provided that this does not harm the child or cause him to lose out on his interests. However, it is not permissible for them to take money to give to another child. Therefore, the mother must seek her son's permission before giving money to his needy siblings, and the son should grant permission to the best of his ability, especially if the need is urgent and concerns his relatives. This would be a fulfillment of filial piety and maintaining kinship ties. The mother should be addressed gently and without harshness. As for sincerity in intention, it requires continuous striving against the self and Satan, abandoning obsessive thoughts, and diligently working to cultivate good intentions.