Beautiful poem!!! Absolutely stunning!!!
The superficial meaning is a traveler trespassing a landlord's area who lives in the village. Its winter solstice (signified by darkest evening of the year) and the location is between a frozen lake and woods. Minutes pass by. The horse thinks its strange to take a break without a nearby farmhouse so he breaks the silence by ringing his harness bells. He describes the woods as lovely, dark and deep but he has miles to go before he can rest. But the deeper more beautiful meaning is that all of us are travelers and we look at escaping the harsh reality of life. So the woods which is a comfortable place of refuge (lovely, dark and deep) that attracts us. We sometimes feel that we have hit emotional rock-bottom and feel in a state of depression.The woods act as an escape from reality. The horse is the common people in our lives and the harness bells is our inner conscience reminding us that we have miles to go (roles, responsibilities and goals to fulfill) before one can truly rest or die peacefully (eternal). It is truly a beautiful poem and it will always be one.