"Once Messenger of Allah ﷺ came to me," and then he narrated the whole narration, i.e. your guest has a right on you, and your wife has a right on you. I then asked about the fasting of David. The Prophet ﷺ replied, "Half of the year," (i.e. he used to fast on every alternate day).  

دَخَلَ عَلَىَّ رَسُولُ اللَّهِ ﷺ فَذَكَرَ الْحَدِيثَ يَعْنِي إِنَّ لِزَوْرِكَ عَلَيْكَ حَقًّا وَإِنَّ لِزَوْجِكَ عَلَيْكَ حَقًّا فَقُلْتُ وَمَا صَوْمُ دَاوُدَ قَالَ نِصْفُ الدَّهْرِ