Answered by Mufti Mohammed Tosir Miah
Is accepting sweets from a person who has bought a house after borrowing loan on interest from a bank permitted?
With regards to eating at a Muslims house whose rizq is unlawful is as follows: if a person’s majority income is lawful and less than half is unlawful, it would be permissible to eat from the food purchased with such income. However, if a person’s majority income is unlawful even though the food itself is halal, but because it was purchased with haram money that food will also be considered haram. (Ahsanul Fatawa p.104 v.8)
Eating Halal is a fundamental aspect for one’s worship being accepted by Allah.
Saiduna Abu Hurayah narrates that the Prophet of Allah said: “Allah is pure and accepts only that which is pure. Allah has commanded the faithful to do that which he commanded the messengers.” And Allah has said: “O you who believe! Eat of the pure things and do right.” Allah has said: “Oh you who believe! Eat of the pure things we have provided you.” Then the Prophet of Allah mentioned a man who journeyed far and dishevelled and dusty and spends out of his hand to the Heavens: “O lord! O Lord! While his food is unlawful, and he is nourished unlawfully, so how can his dua be answered!” (Sahih Muslim)
From this Hadith we can understand that unlawful income does have an effect on ones worship and acceptance of ones duas.
Saaiduna Abu Bakr narrated that the Prophet of Allah said “That body will not enter Paradise which has been nourished with Haram” (Sunan Baihaqi)
Saaiduna Ka`b Bin Ujrah narrates that the Prophet of Allah said, “A body nourished with Haram will not enter Jannah”. (Sunan Tirmizi)
Saaiduna Jabir Bin Abdullah narrates that the Prophet of Allah said, “That flesh will not enter Paradise which has grown from Haram, and all that flesh which has grown from Haram, the fire (of hell) is more worthy of it.” (Musnad Ahmad, Sunan Darimi & Sunan Baihaqi)
Regarding your question, most likely the money he took out has been used to pay for the mortgage, thus, unless your friend is receiving other unlawful means, it will be permissible to accept the sweets.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham.