The most common and most likely answer to this crossword clue is the 4 plus 4 plus 4 letter word COME DOWN WITH
I've seen this crossword clue in The Times
C
O
M
E
D
O
W
N
W
I
T
H
More clues leading to the result COME DOWN WITH
Buddy explains!
The straight part
We know that "Descend from on high bringing/contract" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case descend from on high bringing/contract = come down with.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.