This supplication is used whenever one initially thinks a casual event or occurrence to foretell good or evil, using it as a basis to determine which action he should undertake, but he then denounces such a link, relies on Allah and then says this supplication as an expiation for this act, since it falls under the category of shirk.
Chapter
Forbiddance of ascribing things to omens
2 entries
اللّهُـمَّ لا طَيْـرَ إِلاّ طَيْـرُك، وَلا خَـيْرَ إِلاّ خَـيْرُك، وَلا إِلهَ غَيْـرُك.
Allahumma la tayra illa tayruk, wala khayra illa khayruk, wala ilaha ghayruk.
Translation
O Allah, there is no omen but there is reliance on You, there is no good except Your good and none has the right to be worshipped except You.