"The Messenger of Allah sent Mu'adh [bin Jabal] to Yemen, and said: 'Beware of the supplication of the oppressed; for indeed there is no barrier between it and Allah.'"
أَنَّ رَسُولَ اللَّهِ ﷺ بَعَثَ مُعَاذَ بْنَ جَبَلٍ إِلَى الْيَمَنِ فَقَالَ اتَّقِ دَعْوَةَ الْمَظْلُومِ فَإِنَّهَا لَيْسَ بَيْنَهَا وَبَيْنَ اللَّهِ حِجَابٌ
The Prophet ﷺ sent Muʿadh to Yemen and said, "Be afraid, from the curse of the oppressed as there is no screen between his invocation and Allah."
أَنَّ النَّبِيَّ ﷺ بَعَثَ مُعَاذًا إِلَى الْيَمَنِ فَقَالَ: «اتَّقِ دَعْوَةَ الْمَظْلُومِ، فَإِنَّهَا لَيْسَ بَيْنَهَا وَبَيْنَ اللَّهِ حِجَابٌ۔»
[Machine] The Prophet ﷺ sent Mu'adh ibn Jabal to Yemen and said to him at the end of his instructions, "Beware of the supplication of the oppressed, for there is no barrier between it and Allah." This hadith is reported by Bukhari and Muslim in Sahih from the narration of Waki' and others.
أَنَّ النَّبِيَّ ﷺ بَعَثَ مُعَاذَ بْنَ جَبَلٍ ؓ إِلَى الْيَمَنِ الْحَدِيثَ وَقَالَ فِي آخِرِهِ وَاتَّقِ دَعْوَةَ الْمَظْلُومِ؛ فَإِنَّهُ لَيْسَ بَيْنَهَا وَبَيْنَ اللهِ حِجَابٌ وَأَخْرَجَهُ الْبُخَارِيُّ وَمُسْلِمٌ فِي الصَّحِيحِ مِنْ حَدِيثِ وَكِيعٍ وَغَيْرِهِ
The Prophet ﷺ sent Muʿadh to Yemen and said, "Be afraid, from the curse of the oppressed as there is no screen between his invocation and Allah." (Using translation from Bukhārī 2448)
"اتَّقِ دعوة المظلومِ فإنه ليس بينها وبين الله حجابٌ".