Purchases a/c........Dr
To X 

(Bening the amt which we need to pay the person)

goods sent a/c dr....
  To 'y' a/c.....

Purchase goods acc           dr

      To XYZ ac

(Bengin goods purchased on credit on from xyz)

credit purchase means with out paying we got goods from 
supplier.
purchases a/c dr
         to supplier
(Being goods purchased on credit)

(That means we need to pay the supplier)

credit purchases means without paying the money received 
goods from the supplires is called credit purchases

Entry for credit purchases is
 purchase a\c            dr
    To a's a\c

Purchase A/c     Dr            xxxx
 To XYZ A/c                            xxxx

(Being a goods purchased on credit
from XYZ, which we have to pay the cash
or cheque)

purchase goods on credit