I saw the Messenger of Allah ﷺ extend his hands until I could see the whiteness of his armpits. Sulayman said, meaning during the prayer for rain.
حدثنا ابن أبي عدي عن سليمان يعني التيمي عن بركة عن بشير بن نهيك
رأيت رسول الله ﷺ يمد يديه حتى إني لأرى بياض إبطيه وقال سليمان يعني في الاستسقاء
Its isnad is sahih. Barakah is Barakah bin Uryan, Abu Walid Mujashii, whose reliability and biography were already established at 2221, and we add here that Ibn Abu Hatim gave his biography in Jarh wa Tadil 1/1/432, and reported his validation from Abu Zura.Bashir bin Nuhayk, both names pronounced with a fatha on the first letter and a kasra on the second, Sadusi, Abu Shatha, was a trustworthy Follower. Ajli, Nasai, and Ibn Saad in Tabaqat 7/1/162 confirmed his reliability. Bukhari gave his biography in Tarikh al-Kabir 1/2/105, and Ibn Abu Hatim in Jarh wa Tadil 1/1/379-380.Ibn Hajar said in Tahdhib 1:470, Tirmidhi reported in Ilal from Bukhari that he said, "He did not mention having heard from Abu Hurairah." I do not know where this appears in the book Ilal. I have searched for it as much as I could, but I have not found it!Yes, Ibn Hajar followed this by noting that it is rejected, on the basis of a report from Yahya Qattan which we will mention, but confirming the accuracy of what Ibn Hajar reported is a matter that needs examination.For Tirmidhi reported something different in the book Ilal at the end of Sunan Tirmidhi, 4:396. He said, Mahmud bin Ghaylan told us, Waki told us, from Imran bin Hudayr, from Abu Majliz, from Bashir bin Nuhayk, who said, "I wrote down a book from Abu Hurairah, then I said, 'Do you approve my narrating it from you?' He said, 'Yes.'"Bukhari himself said in Tarikh al-Kabir, in the biography of Bashir bin Nuhayk, "He heard from Abu Hurairah."The report that Tirmidhi narrated was also narrated by Ibn Saad in fuller detail. He said, Affan bin Muslim told us, he said, Yahya bin Saeed Qattan told us, he said, Imran bin Hudayr told us, he said, Abu Majliz told us, from Bashir bin Nuhayk, who said, "I brought to Abu Hurairah the book that I had written, and read it to him, then I said, 'Is this what I heard from you?' He said, 'Yes.'"This isnad and the isnad of Tirmidhi are both sahih, with no defect in either of them.Khatib Baghdadi also narrated it in the book Kifayah, p. 283, through the route of Abu Asim, from Imran bin Hudayr, from Abu Majliz, from Bashir, who said, "I used to come to Abu Hurairah and write down from him, and when I intended to part from him, I came to him and said, 'This is your hadith, may I narrate it from you?' He said, 'Yes.'"This hadith will also come later at 8816, from the report of Arim, from Mutamir bin Sulayman, from his father, with this isnad.Ibn Majah narrated it, 1:199, through the route of Affan, from Mutamir bin Sulayman, from his father, with this isnad, with the wording, "The Prophet ﷺ prayed for rain, until I saw, or it was seen, the whiteness of his armpits." Mutamir said, "I believe this was during the prayer for rain."This report has a problematic wording. For it states in the raised text itself that "he prayed for rain," so there is no point afterward in Mutamir's remark, since an explicit text needs no supposition or preference. I fear that the words "he prayed for rain" may be a mistake introduced by one of the copyists of Ibn Majah's book.Haythami mentioned it in Majma al-Zawaid 10:168 with the wording, "The Messenger of Allah ﷺ used to raise his hands in supplication until the whiteness of his armpits could be seen." He did not mention after it the remark of Sulayman Taymi, which was similarly attributed in Ibn Majah to his son Mutamir.Haythami said, "Bazzar narrated it from his teacher Muhammad bin Yazid, whom I do not know, but the rest of its narrators are trustworthy."In the margin of the original manuscript of Zawaid, in the handwriting of Ibn Hajar, "Note, Muhammad bin Yazid is Abu Hisham Rafii."It appears to me that Bazzar's hadith is this very same hadith.Whatever the case, Haythami should be corrected for including it among the additions, because it carries the same meaning as this hadith, or is an abridgment of it, so it would not count as an addition according to his own terminology, especially since Ibn Majah, one of the authors of the six books, narrated it.Sulayman Taymi's assumption that the raising of hands in supplication was specific to the prayer for rain is not evidence for prohibiting the raising of hands in supplication generally.Ibn Hajar elaborated at length in Fath al-Bari in arguing for its permissibility, and cited many sahih hadiths indicating this, 11:119-121.