Sunan Abi Dawud, Hadith 1531 ⓘ
Narrated AbuHurayrah: The Prophet said: Three supplications are answered, there being no doubt about them; that of a father, that of a traveller and that of one who has been wronged.
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا هِشَامٌ الدَّسْتَوَائِيُّ، عَنْ يَحْيَى، عَنْ أَبِي جَعْفَرٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " ثَلاَثُ دَعَوَاتٍ مُسْتَجَابَاتٌ لاَ شَكَّ فِيهِنَّ دَعْوَةُ الْوَالِدِ وَدَعْوَةُ الْمُسَافِرِ وَدَعْوَةُ الْمَظْلُومِ " .
also referenced under: Hadith 1536 (DarusSalam) & Book 8, Hadith 1531 (USC-MSA)