Mishkat al-Masabih 9 Supplications كتاب الدعوات 21

وَعَنْ عُمَرَ رَضِيَ اللَّهُ عَنْهُ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا رَفَعَ يَدَيْهِ فِي الدُّعَاءِ لَمْ يَحُطَّهُمَا حَتَّى يمسح بهما وَجهه. رَوَاهُ التِّرْمِذِيّ

‘Umar said that when God’s messenger raised his hands in supplication he did not lower them till he wiped his face with them. Tirmidhi transmitted it.