|Bismillaah Al-Hamdulillaah wa salatu wa salaamu 'ala rasulullaah |
The following is from Shaikh Muhammad ibn 'Abdul-Wahhab's book Aadaab Mashee illas Salaah (pages 5-9):
|Allaahumma innee A'oodhu bika [O Allaah verily I seek refuge in You] |
An Adhillah aw udhAllaah [lest I should be misguided or led astray]
Aw azzillah aw uzzAllaah [or lapse or be mistaken]
Aw adhlimah aw udhlamah [or oppress or be oppressed]
Aw ajhalah aw yujhala 'alayyah [or be ignorant or be treated ignorantly.] 
 Reported by Abu Daawood, Tirmidthee, Ibn Maajah, and Nisaa`ee. See: Saheeh Sunanut Tirmidthee (3/151), and Saheeh Sunan Ibn Maajah (2/336).
Source: The Etiquette of Walking to Prayer, by Shaikh Muhammad ibn 'Abdul-Wahhab (rahimahullaah):
Subhanak Allaahuma wa bihamdika ash-hadu anlaa illaaha illa anta astaghfiruka wa atubu ilayk
If I said anything correct, then it is from Allaah (subhanahu wa taa'ala), and if I erred, then that is from me and shaytan.