I do hereby promise on my honor as a Scout,
that I will always and faithfully observe and preserve the traditions of the Order of the Arrow,
Wimachtendienk, Wingolauchsik, Witahemui.

I will always regard the ties of Brotherhood in the Order of the Arrow as lasting,
and will seek to preserve a cheerful spirit,
even in the midst of irksome tasks and weighty responsibilities,
and will endeavor, so far as in my power lies,
to be unselfish in service and devotion to the welfare of others.

About the Obligation

Think the Obligation is hard to memorize? Check out the earliest known version, from 1921:

"I, (your name), do hereby promise on my honor as a Scout, that I will always and faithfully preserve unbroken the secret rites, mysteries, signs and symbols of the Order of the WIMACHTENDIENK WINGOLAUCHSIK, WITAHEMUI, which I have now received or may be taught at any future time. I will always regard the bonds of brotherhood in this Order as sacred and binding, and will seek to preserve a cheerful spirit even in the midst of irksome tasks and weighty responsibilities, and will endeavor, so far as in my power lies, to be unselfish in service and devotion to the welfare of others. I will attend, so far as I am able, all regular and special meetings of the Order and do what I can to promote interest in them." Source