How can one perfectly purify one's intention when inviting friends and relatives for Iftar in Ramadan, while striving for excellence in the food, and avoiding it being for praise or reputation, so as to earn the full reward?

The acceptance of a deed rests on two foundations: sincerity of intention for Allah Almighty, and the righteousness of the deed along with its conformity to the Sunnah (definition). Feeding people is among the righteous deeds, and its reward is multiplied in Ramadan (definition). Any deed not intended for the sake of Allah has no value or reward; rather, it may be a burden upon its doer, for Allah Almighty said: "I am the One Who is most independent of partners. Whoever does a deed in which he associates another with Me, I will abandon him and his shirk (definition)." Among the things that aid in sincerity is the firm belief that benefit and harm are solely in the hand of Allah.