اللهم

Etymology
Extended form of. The origin of the is ar. Theories include a connection with, or a borrowing from , where the final -m is a majestic plural ending. The form is first attested in the (3:26, 5:114, 8:32, 10:10, 39:46). Some interpret it to be a fusion of يَا اللهُ أُمَّ, shortened from يا ألله أمّنا بخير (yā ʾallāhu ʾummanā bi-khayr), meaning "O God, lead us in goodness".

Interjection

 * 1) O God; vocative form of  used in invocations, oaths, etc.