Sunan Abi Dawud 21995
In-book no 1491حَدَّثَنَا عَمْرُو بْنُ عُثْمَانَ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنِي عَبَّاسُ بْنُ عَبْدِ اللَّهِ بْنِ مَعْبَدِ بْنِ عَبَّاسٍ، بِهَذَا الْحَدِيثِ قَالَ فِيهِ وَالاِبْتِهَالُ هَكَذَا وَرَفَعَ يَدَيْهِ وَجَعَلَ ظُهُورَهُمَا مِمَّا يَلِي وَجْهَهُ .
In another version Ibn 'Abbas said: Earnest supplication should be made like this: he raised his hand and made his palms in the direction of his face.