Allahumma

Allāhumma (ٱللَّٰهُمَّ) is a term of address for Allah, the Islamic and Arabic term for one God. It is translated as "O Allāh" and is seen as the equivalent of "Yā Allāh". Some grammarians (such as Sibawayh) argue that it is an abbreviation of يا ألله أمّنا بخير (yā ʾallāhu ʾummanā bi-khayr) (with the meaning of "O God, lead us in goodness"); others have argued without explanation that the suffix ـ مَّ (-mma) takes the place of yā (O). Muslim scholar Ibn ʿĀshūr, in his explanation of Sūrat ʾĀl ʿImrān, suggests that the word Allāhumma is of Hebrew or of Qaḥṭāni derivation.

Christian usage
Hafs ibn Albar, a 9th-10th—century Christian Visigothic author in Al-Andalus, translated the Biblical Psalms into Arabic. Rather than using the standard word for God, "Allah", he used Lahumma or Allahumma inspired by the Hebrew word Elohim.