The Prophet ﷺ said, "Allah is Living and Generous. He feels shy, when a man raises his hands to Him, to send them back empty and disappointed."
عن النبي ﷺ قال: إن الله حي كريم يستحيي إذا رفع الرجل إليه يديه أن يردهما صفرا خائبتين.
Abu Dawud (1488), Tirmidhi (3556), and Ibn Majah (3865) narrated it, the wording being that of the latter two, and Ibn Hibban (876) and Hakim (1/497) graded it sahih. All of them narrated it through various routes from Jafar bin Maymun, the cloth merchant, from Abu Uthman Nahdi, from Salman Farsi, who related it.Its chain is hasan because of Jafar bin Maymun. He is disputed, but his hadith is hasan. Tirmidhi said, "A hasan gharib hadith." Hafiz said in Fath al-Bari (11/143), "Its chain is good."His saying, "that He return them empty and disappointed," means empty, with nothing in them. This refers to joining the hands together during supplication, like a beggar being given something. I do not know of anything in the sunnah, nor in the sayings of the scholars, about spreading the hands apart during supplication. It has been established as sahih that the Prophet ﷺ used to raise his hands during the prayer for rain and in battles, until the whiteness of his armpits could be seen, but it has not been established that he used to spread his hands apart.Said by Shaykh Ibn Uthaymeen, may Allah have mercy on him.