Musannaf Ibn Abi Shayba 3:339

Abu Mu’awiyah narrated to us, from Ubayd Allah ibn Umar, from Abd al-Rahman ibn al-Qasim, from Hafs ibn Asim, who said: It is from the Sunnah in prayer that one spreads his palms, brings his fingers together, and directs them along with his face toward the Qibla.