اتقوا دعوة المظلوم فإنها تصعد إلى السماء كأنها شرارة .
(صحيح) … [ك] عن ابن عمر. الصحيحة 871)
It is reported that the Messenger of Allah, peace and blessings of Allah be upon him, said:
“Fear the supplication of the oppressed, for, indeed, it rushes into heaven like a spark!” .
This hadeeth was narrated by al-Hakim (1/29) from the words of Ibn ‘Umar, may Allah be pleased with them both.
Sheikh al-Albani called the hadith authentic. See “Sahih al-Jami ‘al-sagir” (118), “al-Silsil al-sahih” (871).