Is it permissible for a father who squanders money and asks his married daughters (one employed and the other unemployed) to give him money, especially since he deals in usury and frequently takes out loans?

A father is not permitted to take from his son's money if he is not in need of it. However, if the son is able to honor his father by giving him what he requests, that is more befitting. There is no religious prohibition against giving him money if he will spend it on unlawful things, unless it is known that he requested it specifically to spend on unlawful things; in that case, it is not permissible to give it to him. One of the greatest acts of kindness towards a father is to advise him with good counsel concerning the wrongdoings he commits, such as dealing with usury, and to strive for his guidance and pray for him. A Muslim should not resort to borrowing except out of necessity, and should have good intention and purpose in repaying the debt, for the Prophet, peace and blessings be upon him, said: "Whoever takes people's money with the intention of repaying it, Allah will repay it for him; and whoever takes it with the intention of destroying it, Allah will destroy him."