Hadith 1:32
Hasan (Al-Albani)
Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "Three supplications are answered without a doubt:
the supplication of someone who is oppressed, the supplication of someone on a journey, and the supplication of parents for their children."
حَدَّثَنَا مُعَاذُ بْنُ فَضَالَةَ، قَالَ: حَدَّثَنَا هِشَامٌ، عَنْ يَحْيَى هُوَ ابْنُ أَبِي كَثِيرٍ، عَنْ أَبِي جَعْفَرٍ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ يَقُولُ: قَالَ النَّبِيُّ صلى الله عليه وسلم: ثَلاَثُ دَعَوَاتٍ مُسْتَجَابَاتٌ لَهُنَّ، لاَ شَكَّ فِيهِنَّ: دَعْوَةُ الْمَظْلُومِ، وَدَعْوَةُ الْمُسَافِرِ، وَدَعْوَةُ الْوَالِدِيْنِ عَلَى وَلَدِهِمَا
Original Reference: Al-Adab Al-Mufrad 32