Sunan Abi Dawud, Hadith 1485 ⓘ
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.
حَدَّثَنَا 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 .
also referenced under: Hadith 1490 (DarusSalam) & Book 8, Hadith 1485 (USC-MSA)