(1) باب مَا جَاءَ فِي إِجَابَةِ الدَّعْوَةِ
The tradition mentioned above has also been transmitted by Ibn 'Umar to the same effect through a different chain of narrators. This version has the additional words:
If he is not fasting, he should eat, and if he is fasting, he should leave it.
Reference: Sunan Abi Dawud 3737
In-book reference: Book 28, Hadith 2
English translation: Book 27, Hadith 3728