I am the widow of a man who worked in France and left a son. After his death, I married his brother, who died as well. I wanted to get my pension rights for my first dead husband after the death of my second husband, and so the French authorities sent me the pension file to fill in. The file included a question; whether or not I had subsequently gotten married to another man, and I replied in the negative. After that I received the pension grant for the first husband. Since then, my son, who is married and has five children, and I benefit from the grant.
I wonder whether my reply to the question in the pension file was permissible from the Islamic point of view. Consequently, is my benefiting from the grant lawful or unlawful?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.

The pension salary has two possible cases:

First, it is received in return for an amount of money that is taken from the employee when he was still in his job. In this case, you may take what your husband had paid to the retirement authority, even by using trickery or insinuations, if doing so is necessary to obtain your rights.

Second, the salary is a donation from the retirement authority given according to certain conditions and criteria. In this case, it is not permissible for you to use circumvention to take this money, or give incorrect answers. If you do so, the money will be unlawful.

Allaah Knows best.