Is the questioner sinful for not sending money to his father who claims not to need money, while telling others the opposite?

A son is not obligated to spend on his father if the father owns enough money to suffice him. Therefore, there is no sin upon the questioner if he does not spend on his father, provided his father is well-off. However, spending money on him brings his satisfaction and falls under righteousness towards him. The questioner should seek the reasons that prompt his father to say what has reached him, and he should strive to be dutiful to him and gain his pleasure.