Hadith 5134
وَعَنْ عَلِيٍّ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِيَّاكَ وَدَعْوَةَ الْمَظْلُومِ فَإِنَّمَا يَسْأَلُ اللَّهَ تَعَالَى حَقَّهُ وَإِنَّ اللَّهَ لَا يَمْنَعُ ذَا حق حَقه»
Ali narrates, the Messenger of Allah, peace and blessings be upon him, said: "Beware of the supplication of the oppressed, for he asks Allah for his right, and indeed Allah does not withhold the right from its owner." Its chain of narration is weak. It was narrated by Al-Bayhaqi in Shu'ab al-Iman.