This is the place they hoped before — Exodus

Dickinson wished to escape, to a land flowing with milk and honey. The answer is hinted by a capsule, plank of balm, and escapeless sea.

This is the place they hoped before, ¹
Where I am hoping now.
The seed of disappointment grew
Within a capsule gay,
Too distant to arrest the feet ⁵
That walk this plank of balm－
Before them lies escapeless sea－
The way is closed they came.

(F.1284/J.1264)

[1] the place:: a land flowing with milk and honey. they:: the children of Israel.
[2] I:: Emily Dickinson was hoping to escape to a new land.
[3] seed:: the offspring of Israel.
[4] a capsule gay:: the ark of the testimony.
[5] Too distant:: too hard for people to follow the Ten Commandments.
[6] walk:: to conduct, behave one's life. plank:: a flat slab of stone _{(OED 3a)}; an item or article _{(OED 5)}. balm:: anything that heals or soothes pain. plank of balm:: the testimony.
[7] escapeless sea:: the Red Sea.
[8] they:: Egyptians closed their way back to Egypt.