Understanding "Whoever Obeys Allah & His Messenger" - Meaning, Grammar, and Commentary

This is a question which involves Arabic grammar.

On reading Qadi Iyad's Shifa' on page 8, I read that a man once said in front of the Prophet "Whoever obeys Allah and His messenger has been rightly guidedand whoever reels against them both (joining them together by using the dual form..." The Prophet said to him "What a bad speaker you are" since that grammatical device implies equality.

However, in Wayfarers to God, Habib Ali al Jifri states in reference to the hadith "that Allah and His envoy be dearer to you than other than these two""placing the sentence in the dual pronoun to teach us that there is no separation between the love for Allah and love for His envoy" (p. 188).

In view of these apparently conflicting reports is the dual pronoun appropriate to be used in reference to Allah and His messenger?