Require helping, left lying in quicksand (3)
I believe the answer is:
ask
'require' is the definition.
(I know that require is a more specific form of enjoin)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for ask that I've seen before include "Make enquiry" , "Issue invitations" , "Request, invite" , "Pose" , "Put a question" .)