Uthman bin Abu As reported,
The Prophet ﷺ said, "The gates of heaven are opened at midnight, and a caller calls out, 'Is there anyone supplicating, that his prayer may be answered? Is there anyone asking, that he may be granted? Is there anyone distressed, that his distress may be relieved?' No Muslim makes a supplication except that Allah 
answers him, except for a prostitute who trades with her body, or a tax collector."
Azami 10947
Hasanعن عثمان بن أبي العاص الثقفي
عن النبي ﷺ قال: تفتح أبواب السماء نصف الليل، فينادي مناد: هل من داع فيستجاب له، هل من سائل فيعطى، هل من مكروب فيفرج عنه، فلا يبقى مسلم يدعو بدعوة إلا استجاب الله عز وجل له، إلا زانية تسعى بفرجها، أو عشارا.
Tabarani reported it in Al-Kabir (9/51) and in Al-Awsat (Majma Bahrayn, 1381), from Ibrahim bin Hashim Baghawi, who said, our teacher Abdul-Rahman bin Salam Jumahi told us, our teacher Dawud bin Abdul-Rahman Attar told us, from Hisham bin Hassan, from Muhammad bin Sirin, from Uthman bin Abu As, and he mentioned it.Tabarani said, "No one narrated it from Hisham except Dawud, and Abdul-Rahman narrated it alone."I say, Abdul-Rahman bin Salam is Jumahi, their freedman, Abu Harb Basri. Abu Hatim said, "Truthful." Ibn Hibban mentioned him among the trustworthy narrators (8/379). So his being the sole narrator does not harm the hadith, for at the very least it is hasan.