windfall vs manna from heaven

windfall and manna from heaven both are nouns.

Word	Noun	Adjective	Verb	Adverb
windfall	Yes	No	No	No
manna from heaven	Yes	No	No	No

As nouns, windfall and manna from heaven are synonyms defined as:

windfall and manna from heaven: a sudden happening that brings good fortune (as a sudden opportunity to make money)

Other synonyms of windfall include bonanza, boom, bunce, godsend, gold rush, gravy.

windfall (noun)	manna from heaven (noun)
a sudden happening that brings good fortune (as a sudden opportunity to make money)	a sudden happening that brings good fortune (as a sudden opportunity to make money)
fruit that has fallen from the tree	(Old Testament) food that God gave the Israelites during the Exodus