Hadith 1490
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 .
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
Sahih (Al-Albani)
Sunan Abi Dawud 1490 · Book 8, Hadith 75