Hadith: Arabic Text followed by English Translation.
عَنْ أَبِي هُرَيْرَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ
ثَلاَثُ دَعَوَاتٍ مُسْتَجَابَاتٌ لاَ شَكَّ فِيهِنَّ دَعْوَةُ الْوَالِدِ وَدَعْوَةُ الْمُسَافِرِ وَدَعْوَةُ الْمَظْلُومِ
أخرجه أبو داود ١٥٣٦ و حسنه الألباني في صحيح أبي داود
Narrated Abu Hurayrah:
The Prophet (ﷺ) 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.
Sunan Abi Dawud 1536 and classed as Hasan by Albani in Saheeh Abi Dawud.