Hi, usually licking of the paws is either a sign of itching, or pain. He may have gotten stung, but if he's not allergic to bees or wasps, he may not show any signs of allergy symptoms like swelling or hives, but it may still have hurt him, so he's licking it. He may have stepped on something sharp like a rock, or pine cone that may have hurt him. You did the right thing by giving him a Benedryl, just in case he was stung or bitten by something. You've checked his paws for any signs of a sting or cut. I would just keep an eye on him, and watch for signs, and if he continues to lick, watch which paw it is and recheck it carefully for anything like a cut, or something stuck in his paw like glass or a stone. He may have just stepped on something and bruised his paw pad. Watch to see how he walks on his paws, look for signs of limping, or favouring when he walks. I hope he's okay. Please keep us posted.