Mustadrak al-Hakim 1217

ʿAlī b. Ḥamshādh al-ʿAdl > Hishām b. ʿAlī al-Sadūsī > Sahl b. Bakkār > Muḥammad b. ʿAbd al-ʿAzīz b. ʿAbd al-Malik from his father > Ṭalḥah b. Yaḥyá > Arsalanī Marwān > Ibn ʿAbbās Asʾaluh > Sunnah al-Iāstisqāʾ

"The sunnah of seeking rain refers to the sunnah of performing prayer on the two Eids, except that the Messenger of Allah ﷺ turned his cloak inside out and placed his right over his left and his left over his right and prayed the two units of prayer. He magnified during the first unit with seven takbeerat and recited "Subhan Allahi-l-A'la" and recited "Hal ataaka hadithu-l-ghashiya" in the second unit, and magnified it with five takbeerat."

حَدَّثَنِي عَلِيُّ بْنُ حَمْشَاذَ الْعَدْلُ ثنا هِشَامُ بْنُ عَلِيٍّ السَّدُوسِيُّ حَدَّثَنِي سَهْلُ بْنُ بَكَّارٍ ثنا مُحَمَّدُ بْنُ عَبْدِ الْعَزِيزِ بْنِ عَبْدِ الْمَلِكِ عَنْ أَبِيهِ عَنْ طَلْحَةَ بْنِ يَحْيَى قَالَ أَرْسَلَنِي مَرْوَانُ إِلَى ابْنِ عَبَّاسٍ أَسْأَلُهُ عَنْ سُنَّةِ الِاسْتِسْقَاءِ فَقَالَ

«سُنَّةُ الِاسْتِسْقَاءِ سُنَّةُ الصَّلَاةِ فِي الْعِيدَيْنِ إِلَّا أَنَّ رَسُولَ اللَّهِ ﷺ قَلَبَ رِدَاءَهُ فَجَعَلَ يَمِينَهُ عَلَى يَسَارِهِ وَيَسَارَهُ عَلَى يَمِينِهِ فَصَلَّى الرَّكْعَتَيْنِ يُكَبِّرُ فِي الْأُولَى سَبْعَ تَكْبِيرَاتٍ وَقَرَأَ سَبِّحِ اسْمَ رَبِّكَ الْأَعْلَى وَقَرَأَ فِي الثَّانِيَةِ هَلْ أَتَاكَ حَدِيثُ الْغَاشِيَةِ وَكَبَّرَ فِيهَا خَمْسَ تَكْبِيرَاتٍ» هَذَا حَدِيثٌ صَحِيحُ الْإِسْنَادِ وَلَمْ يُخَرِّجَاهُ