गुरुर्ब्रह्मा गुरुर्विष्णुर्गुरुर्देवो महेश्वरः । गुरुरेव परं ब्रह्म तस्मै श्रीगुरवे नमः ॥
Guru
Guru Brahma Shloka
A verse of respect to the teacher, who is likened to Brahma the creator, Vishnu the preserver and Maheshvara (Shiva), and to the highest Brahman itself. It is taken from the Guru Gita (verse 58 of the long version on Sanskrit Documents). It is recited on Guru Purnima, in schools and before lessons. The popular form of the third line reads Guruh sakshat param brahma; the Guru Gita text reads Gurureva param brahma, and that is the wording given here.
Wording checked against: Sanskrit Documents: Guru Gita, long version, verse 58 https://sanskritdocuments.org/doc_giitaa/gurugita.html; Greenmesg: Guru Stotram (same wording, notes it is found in Guru Gita) https://greenmesg.org/stotras/gurudeva/guru_stotram.php; Shlokam.org: Guru Brahma Guru Vishnu (variant 'गुरुः साक्षात् परब्रह्म') https://shlokam.org/shloka/guru-brahma-guru-vishnu.htm. Editions differ slightly; follow your family's or guru's version if it differs.