Assalamu alikum,My question is dat-My father took a shop on rent around 15 years ago. An argument arose between landlord and my father, the landlord publicly tried to attack my father after 2 years.some people of area tried to resolve d matter. My father agreed to vacate shop on date decided by people ,my father received an amount around 30 thousands Indian rupee. He informed us that the landlord was using half of the shop himself so he returned me half of the rent for 30months.my father lent this amount to his younger brother for his daughter's marriage expenses around 12 years ago.now 2 years before he returned partly amount of 17 thousands so mother bought a refrigerator for the house.Recently i tried to enquire about source of money fearing that it may be unlawful to take back the rent from landlord. My father informed me that he had given security deposit of around 40000 to landlord and he returned that moneyAnd landlord's mother asked my father to forgive remaining 10 thousands.i dont know what to believe knowing my father can tell lies.but he is saying that he can take oath on Quran that the money is halal and it wz his security deposit. I cant enquire from the landlord as his family is also dishonest. I am fearing may be my father received that money for vacant shop bt I m nt sure.i want to know that is it lawful for me to use that refrigerator bought from that money.

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 ʻalayhi wa sallam, is His slave and Messenger.

What you have mentioned in the question indicates that you suffer from Waswaas (obsessive satanic whisperings). If this is the case, you are advised to disregard those whisperings and any similar thoughts that come to your mind in order to avoid incurring more serious consequences and cause damage to your life and religiosity.

To sum up the answer to your question, there is no blame on you for using this fridge or any other item of property that was purchased with this money. If there arises evidence that the father was not entitled to it, then the forbidden nature of the act falls under the father's responsibility.

We highlight here a valuable quote from Ibn Taymiyyah  related to this, which can serve as a great principle governing interactions among people. He said,

“The presumption concerning whatever is in the possession of a Muslim and what he claims to be his property, is that it is his rightful property. If I do not know the status of the property in his possession, I base judgment on the presumption. Further, if in the same instance he did unlawfully take possession of that Dirham (for example), and I did not know, then I would then have been unknowing, and what is unknown is (effectively) non-existent.” [Majmoo‘ Al-Fataawa]

Allaah Knows best.