From Aswad ibn ‘Amir who narrated: I offered Fajr Salah behind Rasulullah. When he finished it with the salam, he turned himself, raised his hands and made dua’.
(I’la al Sunan vol 3 pg 207, al Mu’jam al Kabir of Imam Tabarani vol 2 pg 202)

From al Fadl ibn ‘Abbas: Rasulullah said: Prayer is in twos. The tashahhud is to be recited at every two rakahs. Be submissive and humble and show your helplessness. And raise your hands towards your Lord so that your palms face you and say: My Lord, my Lord! As for the one who does not do this, this prayer is like that and that. In another version it is reported: Whoever does not do so, his prayer is defective and incomplete.
(Sunan Tirmidhi vol 1, pg 50, Sahih ibn Khuzayma vol 2, pg 220, Ibn Majah pg 95)

From Abu Hurayra: After turning in salam, Rasulullah raised his hands while he was yet facing the Qibla and made dua’: O Allah! Save Walid ibn Walid!
(Ma’rif al Sunan, vol 3, pg 122)

More traditions can be found on this issue from Anas in Amal al Yawm wal Layla, ibn ‘Abbas in Tabarani’s Mu’jam al Kabir, Habib ibn Salama al Damari in Kanz al ‘Ummal.