My 4yr Bengal Tomcat Benny Came In From Outside Last

my 4yr bengal tomcat Benny came in from outside last evening limping I check his back left foot, botton was a slice gash cut ... I bathed it and put some antaceptic cream and wrapped it ... he slept in the bathroom last night ... its still wrapped ... I just took in his morning cat biscuits and water ... he ate and he was purring ... but hes staying still ... thought of making a kitty litter box for him, as there are many stairs down to back yard ... what should I do NOW... grace