It always felt to me — a wrong

It always felt to me — a wrong
To that Old Moses — done —
To let him see — the Canaan —
Without the entering —

And tho' in soberer moments —
No Moses there can be
I'm satisfied — the Romance
In point of injury —

Surpasses sharper stated —
Of Stephen — or of Paul —
For these — were only put to death —
While God's adroiter will

On Moses — seemed to fasten
With tantalizing Play
As Boy — should deal with lesser Boy —
To prove ability.

The fault — was doubtless Israel's —
Myself — had banned the Tribes —
And ushered Grand Old Moses
In Pentateuchal Robes

Upon the Broad Possession
'Twas little — He should see —
Old Man on Nebo! Late as this —
My justice bleeds — for Thee!
                             F521 (1863)  J597


Dickinson was skeptical about Christianity, particularly in its portrayal of God as all-knowing, all-powerful, and all-good. Her path to this skepticism, which set her apart from family, friends and townspeople, seems to have come at least in part from reading the family Bible. She says as much in the opening lines of this poem: she always felt God behaved badly towards Moses, showing him the Promised Land but forbidding him to enter it. 
It was Moses, after all, who had led the suffering Israelites out of Egypt forty years before. Most people remember the stories of the plagues, the parting of the Red Sea and the manna from heaven. It was Moses who brought the tablets with the Ten Commandments down from God. He is considered chief among the Patriarchs. Yet God denied him Canaan, the promised destination, because of what seems a forgivable and uncharacteristic failure: when God told him that if he spoke to a rock it would gush forth enough water to save the thirsty Israelites, Moses instead struck the rock with his rod and, probably more to the point, didn't credit God – something he had done throughout his long and heroic leadership.   

Moses looking at the Promised Land he was
forbidden to enter

Dickinson calls God's actions a tease, a "tantalizing Play", something akin to a cruel boy egging on a boy he knows to be his inferior simply to flaunt his own superiority. She makes a similar criticism in  F304  where the "June Bee" invites a schoolboy to a "Race" that he has no chance to win. The bee "evades" and "teases" and then goes back to the "Royal clouds" where the whole sky mocks the boy.

Although she admits that "in soberer moments" she finds the Biblical accounts of Moses to be a fantasy, a "Romance", Dickinson compares Moses's fate to that of Stephen, the first Christian martyr, stoned to death for his faith, and the apostle Paul who was reportedly beheaded at the command of Nero. Stephen and Paul were simply put to death by peers or rulers for their beliefs, while Moses had to gaze upon the land he had led his people towards for forty years, knowing that the god under whom he served was forbidding him to ever set foot in it. A sad, if not bitter, moment indeed, with God rubbing a bit of salt into the wound. It is God's "adroiter will", and Dickinson is here making a word play (per the invaluable Emily Dickinson Lexicon) on the French roots of "adroit": "to right, or "rightly". What she means is "cunning" and "clever" – nothing about this is "right" to her.
Some might say that God was showing Moses some mercy when he allowed Moses to see Canaan, providing some sense of closure. But not Dickinson. First, she blames the Israelites who seem to have provoked Moses into his unscripted whacking of the rock by their quarreling and complaining. She would have banned them from the promised land instead of "Grand Old Moses". 
In the last two lines of the poem, Dickinson addresses Moses directly: Old grandfather, there on Mt. Nebo looking out over what you should have possessed – "My justice bleeds – for Thee!" It is a ringing end to a well-reasoned poem.



Here are some of the pertinent Biblical passages:
The Fault of Moses
Numbers 20:2-12
2 Now there was no water for the community, and the people gathered in opposition to Moses and Aaron. 3 They quarreled with Moses and said, “If only we had died when our brothers fell dead before the LORD! 4 Why did you bring the LORD’s community into this wilderness, that we and our livestock should die here? 5 Why did you bring us up out of Egypt to this terrible place? It has no grain or figs, grapevines or pomegranates. And there is no water to drink!”
6 Moses and Aaron went from the assembly to the entrance to the tent of meeting and fell facedown, and the glory of the LORD appeared to them. 7 The LORD said to Moses, 8 “Take the staff, and you and your brother Aaron gather the assembly together. Speak to that rock before their eyes and it will pour out its water. You will bring water out of the rock for the community so they and their livestock can drink.”
9 So Moses took the staff from the LORD’s presence, just as he commanded him. 10 He and Aaron gathered the assembly together in front of the rock and Moses said to them, “Listen, you rebels, must we bring you water out of this rock?” 11 Then Moses raised his arm and struck the rock twice with his staff. Water gushed out, and the community and their livestock drank.
12 But the LORD said to Moses and Aaron, “Because you did not trust in me enough to honor me as holy in the sight of the Israelites, you will not bring this community into the land I give them.”


The Death of Moses
Deuteronomy 34:1-6
Then Moses climbed Mount Nebo from the plains of Moab to the top of Pisgah, across from Jericho. There the Lord showed him the whole land—from Gilead to Dan, 2 all of Naphtali, the territory of Ephraim and Manasseh, all the land of Judah as far as the Mediterranean Sea, 3 the Negev and the whole region from the Valley of Jericho, the City of Palms, as far as Zoar. 4 Then theLord said to him, “This is the land I promised on oath to Abraham, Isaac and Jacob when I said, ‘I will give it to your descendants.’ I have let you see it with your eyes, but you will not cross over into it.”
5 And Moses the servant of the Lord died there in Moab, as the Lord had said. 6 He buried him[a] in Moab, in the valley opposite Beth Peor, but to this day no one knows where his grave is.