(Whoso obeyeth Allah and the messenger) this verse was revealed about Thawban, the client of Allah's Messenger (pbuh) who said: “I am afraid not to meet you in the Hereafter, O Messenger of Allah!” This is because he loved him intensely and could not bear being away from him. Allah's Messenger saw the change in him and so Allah mentioned the honour bestowed on him, saying: whoever obeys Allah regarding the obligations and obeys the Prophet regarding the prophetic practices (they are) in Paradise (with those unto whom Allah hath shown favour, of the Prophets) Muhammad (pbuh) and the other prophets, (and the saints) the best among the Companions of the Prophet (pbuh) (and the martyrs) those who were martyred in the way of Allah (and the righteous) the righteous among the Community of Muhammad (pbuh). (The best of company are they) in Paradise!
