All Muslims are but brothers. A Muslim is thought of in the best terms and one should regard him in best terms and in a positive manner in everything that he says and does. A Muslim should not think of his brother in negative and suspicious manner. Suspicion is the falsest of the speeches. The Muslim is a brother of his fellow Muslim and he should love him for himself of good and hate for him that he would hate for himself. If a Muslim offers you food or drink, the basic principle is that you should think positively of him unless you clearly see something to the contrary. No attention should be paid to waswas (devilish whispers or notions that the Shaytan may put in one’s mind) or doubts that are not based on sound proof.
Al-Bukhari (5144) and Muslim (2563, 4917) narrated from Abu Hurayrah that the Messenger of Allah (blessings and peace of Allah be upon him) said: “Beware of suspicion, for suspicion is the falsest of speech. Do not seek out one another’s faults; do not spy on one another; do not compete with one another; do not envy one another; do not hate one another; do not turn away from one another. Be, O slaves of Allah, brothers.”
In ‘Awn al-Ma‘bood (9/2195-2196) it says:
“Beware of suspicion” means: beware of the following suspicion or beware of negative thinking, for suspicion is an accusation that comes to mind without any evidence.
Al-Bayhaqi narrated in ash-Shu‘ab (8344) that Ja‘far ibn Muhammad said: If you hear something about your brother that you dislike, then look for excuses for him, from one to seventy excuses; if you find an excuse for him (all well and good), otherwise say: Perhaps he has an excuse that I do not know of.
Al-‘Allamah Ibn Baz (may Allah have mercy on him) said:
What is legislated for the believer is to respect his brother if he offers an excuse to him, to accept his apology if possible, and to think positively of him as much as possible, striving to keep hearts free of resentment and aiming to bring about unity and co-operation in doing good? It was narrated from ‘Umar (may Allah be pleased with him) that he said: Do not think badly of any word uttered by your brother when you can find a good interpretation for it. End quote fromMajmoo‘ Fatawa Ibn Baz, 26/365
So it is better for you to eat and drink from what your Muslim brother offers you and never pay attention to waswas and suspicion
Do not think badly of him unless you see clear proof to the contrary or you think it most likely that that is the case, on the basis of corroborating evidence that you say you have, if there is a reason to be cautious.
And Allah knows best.