how to insert a newline \n after x numbers of words, with AWK or Sed

Question

I have this in one line:

We were born in the earth beyond the land

I want it in 3 words lines, to be like this:

We were born
in the earth 
beyond the land

Answer 1

$ xargs -n3 < file
We were born
in the earth
beyond the land

$ egrep -o '\S+\s+\S+\s+\S+' file 
We were born
in the earth
beyond the land