Bitachon regarding the problems of others:[1]
The attribute of trust is only considered virtuous when it is regarding one’s personal problems and challenges. However, one should never exercise trust in G-d regarding the problems of another individual. Rather, one must do on his power to help them and assist them in their issue. It goes without saying that the virtuous idiom of Gam Zu Litova should not be expressed regarding the problems of another individual, but rather only regarding those of one’s own.
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[1] Igros Kodesh Rayatz 3 p. 76 in name of Baal Shem Tov “However to use the attribute of Bitachon on another person is a transgression. If one sees that his friend is suffering from something and he says that certainly Hashem will help him, this is a great evil, and rather the person must exert effort in praying and requesting mercy on behalf of that individual.”