Wiktionary
fools rush in where angels fear to tread
prov. A person who does not plan ahead and think through becomes involved in risky or unfavorable situations which prudent people avoid.
Wikipedia
Fools rush in where angels fear to tread
The line For fools rush in where angels fear to tread. was first written by Alexander Pope in his poem An Essay on Criticism. The poem first appeared in 1711.
It has since been used as follows:
Usage examples of "fools rush in where angels fear to tread".
Haven't you ever heard the phrase 'Fools rush in where angels fear to tread'?