When the Amalekites attacked Israel in Rephidim Moses went to the top of the hill and gazed down at the skirmish from on high. He had two men, Aaron and Hur, supporting his hands to the left and the right. Moses knew his mission. He had to keep his hands lifted in order to ensure victory from below. But a time came when he needed the support of his brothers to either side. (Full story at Exodus 17:8-15.)
I'm sure there were times when his mind drifted, when he could do no more, and he completely resigned himself to the strong arms of those around him.
Aside from the exhortation to have a couple of covenant buddies to help us in our missions, this passage also provides a foreshadowing of Christ on the Cross. Like Moses, Christ was lifted above a valley and his persistence in following through had everything to do with our victory over sin. There may have been times when he, too, looked into the bleak souls of the criminals, crucified on either side, and - seeing their utter helplessness in the face of such an enemy - was encouraged in Love to stay the Course of his Mission. Sometimes one look into the eyes of one completely ravaged by sin raises within us the almighty compassion of the Creator.