"Three supplications are accepted , there is no doubt in them (about them being accepted): The supplication of the oppressed, the supplication of the traveler, and the supplication of a parent against his child."  

قَالَ رَسُولُ اللَّهِ ﷺ ثَلاَثُ دَعَوَاتٍ مُسْتَجَابَاتٌ لاَ شَكَّ فِيهِنَّ دَعْوَةُ الْمَظْلُومِ وَدَعْوَةُ الْمُسَافِرِ وَدَعْوَةُ الْوَالِدِ عَلَى وَلَدِهِ