Picked up in the field, finally being rested (7)
I believe the answer is:
gleaned
'picked up in the field' is the definition.
(glean can mean to gather grain)
'finally being rested' is the wordplay.
'finally' says to take the final letters.
'rested' becomes 'leaned' (as in leaning or resting on something).
The last letter of 'being' is 'g'.
'g'+'leaned'='GLEANED'
(Other definitions for gleaned that I've seen before include "Harvested, gathered" , "A legend (anag.)" , "Found out" .)