ENOfficial
He reported God’s messenger as saying, “Three supplications are answered, there being no doubt about them: that of a parent, that of a traveller, and that of one who has been wronged.” Tirmidhi, Abu Dawud and Ibn Majah transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " ثَلَاثُ دَعَوَاتٍ مُسْتَجَابَاتٍ لَا شَكَّ فِيهِنَّ: دَعْوَةُ الْوَالِدِ وَدَعْوَةُ الْمُسَافِرِ وَدَعْوَةُ الْمَظْلُومِ ". رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَابْنُ مَاجَهْ
sunnah.com