حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم ذَكَرَ يَوْمَ الْجُمُعَةِ فَقَالَ ‏"‏ فِيهِ سَاعَةٌ لاَ يُوَافِقُهَا عَبْدٌ مُسْلِمٌ وَهُوَ قَائِمٌ يُصَلِّي يَسْأَلُ اللَّهَ شَيْئًا إِلاَّ أَعْطَاهُ إِيَّاهُ ‏"‏ ‏.‏ وَأَشَارَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِيَدِهِ يُقَلِّلُهَا ‏.‏

Yahya related to me from Malik from Abu'z Zinad from al-Araj fromAbu Hurayra that the Messenger of Allah, may Allah bless him and granthim peace, mentioned the day of jumua and said, "There is a time in itwhen Allah gives to a muslim slave standing in prayer whatever he asksfor," and the Messenger of Allah, may Allah bless him and grant himpeace, indicated with his hand how small it was. Translation Not Available

Book Ref: Muwatta Imam Malik Book 5 Hadith 239
Web Ref:  Muwatta Imam Malik Book 5 Hadith 16