His father receives pension for his work in France

Q: My father worked in France for four or five years, then he returned to Morocco. They used to send him his pension years later. After his death, (Part No. 11; Page No. 216) the pension was transferred to my mother, who asked all of my brothers to sign a document related to the pension. When I refused, she became extremely angry with me. I regarded every cent over the sum deducted from my father's salary in return for his work as Haram (unlawful). However, I signed the document to satisfy her after all of my brothers signed it to enable my mother to receive the pension via a bank.Did I commit a mistake by signing this document? Is the pension, especially the sum that exceeds the deduction taken from my father's salary during his work, Haram?

A: If your father deserves this sum in return for his lawful work, all of you shall inherit it after his death, as it is the right of you all. But, if it is in return for unlawful work, it is Haram to him and to you, and you should not take it.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family and Companions.