What is the ruling on taking gifts, food items from non-Muslim neighbors or friends (even Muslim brothers) knowing that they earn their money through Riba (interest)?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Gifts can be accepted from non-Muslims because the Prophet used to accept gifts from non-Muslims and offer them gifts.

‘Ali narrated that “Caesar offered a gift to the Prophet and he accepted it from him; Kaiser also offered him a gift and he accepted it, and other kings offered him gifts and he accepted them”. [Ahmad and At-Tirmithi]

Al Bukhaari and Muslim  also narrated that: “Once Ukaidar head of Dawmat-ul-Jandal, gifted the Prophet a garment of silk [and he ordered it to be divided as a head covering among his daughter Fatimah and other girls also named Fatimah]

However, some scholars disliked the gifts offered by non-Muslims and even ordered not to accept it for the Hadeeth narrated byAhmad, At-Tirmithi and Abu Dawood that Ayadh Ibn Himaar offered a gift to the Prophet (a she camel). The Prophet said: “Did you become Muslim?” He replied: “No” Thereupon, Prophet said: “I have been ordered not to accept presents from polytheists.”

Abdur-Razaaq also narrated from Ka'b Ibn Malik that ‘Amir Ibn Maalik, the great knight, came to the Prophet and gave him a present. The Prophet said: “I do not accept gifts from a polytheist”.

The most preponderant opinion is that it is lawful to accept gifts and presents from non-Muslims if their objective is not to tempt the Muslim and persuade him to be on their side as this is forbidden.

So, if the Muslim realizes that there is a bad objective behind the present, he should not accept it. The Muslim accepts the present of any non-Muslim whom he thinks could be attracted by Islam and become Muslim.

It is lawful for you to eat from what your friends offer you even if they deposit their money in usury-taking banks. The Prophet was once invited in a Jewish woman's house and it is known that Jews deal in Riba.

As a rule, it is lawful to eat from the food of a person whose earnings are mixed between lawful money and ill-gotten money. But it is unlawful to eat from the food of a person whose earnings are all from what is forbidden or most of them are from forbidden transactions.

Allah knows best.