"Tafa'alu bil-khayr tajiduh" (Be optimistic about goodness and you will find it), is this a noble Prophetic Hadith?

The mentioned wording was not found in the books of Sunnah, but it was reported in the Two Sahihs and other collections that the Messenger of Allah, peace and blessings be upon him, said: "There is no tiyarah (evil omen), and the best of it is fa'l (good omen)," and fa'l was interpreted as a good or pleasant word.