This text comes from Songs of Innocence and of Experience (1826), a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Transcription(contributor provided)
The Little Boy found
The little boy lost in the lonely fen,
Led by the wand'ring light,
Began to cry; but God ever nigh,
Appeard like his father in white.
He kissed the child & by the hand led
And to his mother brought,
Who in sorrow pale, thro' the lonely dale
Her little boy weeping sought.