[Avodah] ONE HAND vs. TWO HANDS

[Richard Wolberg]

I recently asked the following question and found it strange that not even one person
responded. 
In Pinchas 27:18 it states: ''...v'samachta es yadcha..." (lean your hand [singular]). 
Five p'sukim later 27:23 it states: ''Vayismoch es yadav alav...'' (He leaned his hands [plural]). 
And the pasuk immediately preceding (vs.22) states ''Vayaas Moshe kaasher tziva HaSem oso...'' 
How could it say that he did as he was commanded? He was commanded to lean ONE hand and 
he leaned TWO hands. Such a big deal is made out of his striking the rock instead of speaking to it, 
so how come he wasn't penalized for following the exact instructions (laying ONE instead of TWO
hands) and how could the Torah state that he did as HaShem commanded him?

So I did some research on my own and found that the Ramban addressed
the very question, though I didn't find it a satisfying answer. He says: ''Take thee Joshua
the son of Nun, means that 'when your time [to die] comes, you shall take Joshua,'' [but
it is not a command to do so now]. And Scripture completed [this episode] by saying that 
Moshe did so wholeheartedly...''  This refers to the fact that although Moshe was only 
commanded (in pasuk 18) to lay ''his single hand upon him,'' he laid his 'HANDS' upon 
him, which shows that he appointed his successor whole-heartedly, although he knew that
he was now to die.''

The reason given doesn't explain or address the fact that Moshe was commanded to lean ONE hand
and instead he leaned TWO. The Torah is m'dakdek about everything else, so why should this be
different. My feeling is that since nothing was made of it, the Ramban justified it by praising Moshe for
using BOTH hands.

I ran this question by my class and actually got a very interesting answer from an 86 year old woman.
She said that when Moshe was commanded to lean his hand, it didn't say which hand (right or left).
Consequently, he laid both hands so that one of them had to be the correct one.