"....And we are put on earth a little space,
That we may learn to bear the beams of love
And these black bodies and this sunburnt face
Is but a cloud, and like a shady grove.
For when our souls have learn'd the heat to bear,
The cloud will vanish, we shall hear His voice,
Saying, 'Come out from the grove, my love and care
And round my golden tent like lambs rejoice...',"
(Little Black Boy)
"Planting these Oaken Groves: Erecting these Dragon Temples" (Erdman 170)
"Patriarchal Pillars & Oak Groves) over the whole Earth..." (Erdman 171)
"If we are wrathful Albion will destroy Jerusalem with rooty Groves
If we are merciful, ourselves must suffer destruction on his Oaks:
Why should we enter into our Spectres. to behold our own corruptions
O God of Albion descend! deliver Jerusalem from the Oaken Groves!"
(Erdman 184: Jerusalem Plate 38/43 lines 9-12)
"And build this Babylon & sacrifice in secret Groves" (Jerusalem, 60.23; E210)
"For a Spectre has no Emanation but what he imbibes from decieving
A Victim! Then he becomes her Priest & she his Tabernacle.
And his Oak Grove. till the Victim rend the woven Veil."
( Jerusalem, 65.60-62; E217) (See also Matthew 27:51)
"Till I turn from Female love
And root up the Infernal Grove,
I shall never worthy be
To step into Eternity.
Let us agree to give up love,
And root up the Infernal Grove;
Then shall we return and see
The worlds of happy Eternity. (My Spectre)
In his Complete Works Blake used the word 'grove' (or groveling) 26 times; you might wonder how Blake related the two words or about their etiology.
Notice that the 'love' in the last verse is the 'female love' of the earlier one. This 'love' in Blake's poetry is nothing like godly love; in fact it's just the opposite; it's love of fallen materiality- love of things, like Money, or Golf, or Whiskey, or your Stomach; see (See Philippians 3:19)
So what did Blake mean with his groves. Damon said it's a "symbol of error"; I say it's a symbol of the 'fallen material world' where the Druid Priests built their Temples and Altars.
Blake used thousands of words to describe his primary myth: Creation, Fall, Redemption, Return, and many many pictures to portray it, and many, many capsules of two lines that state it. He wanted us to get it.