Musannaf Ibn Abi Shayba 21:288

Abu Khalid al-Ahmar narrated to us, from Ibn ‘Ajlan, from al-‘Abbas ibn Dharih, from Ibn ‘Abbas, who said: "Sincerity (al-ikhlas) is like this," and he gestured with his finger. "And supplication (al-du’a) is like this," and he gestured with the palms of his hands. "And seeking guidance (al-istikhara) is like this," and he raised his hands and turned the backs of them toward his face.