Sefiras HaOmer: Forty Nine Equals Fifty

וספרתם לכם ממחרת השבת שבע שבתות תמימות תהיינה

"and you shall count...seven complete weeks..."

תספרו חמשים יום

"and you shall count fifty days"

The commentators all ask the obvious question: Are we to count seven full weeks (only 49 days) or 50 days?

The Rebbe explained this apparent contradiction with the following parable: Someone buys a puzzle that claims to have 500 peices. He works on the puzzle until completion, all the while counting every piece. Once he finishes the puzzle, he realizes that there are only 499 pieces and immediately files a complaint with the company. He is told that now that he has completed the puzzle, he has a new entity that he did not have before. He now has the completed puzzle. That is a piece in and of itself and hence, 500 peices.

So too with counting the Omer. The exercise of Sefiras haOmer is intended to change a person. The hope is that if the seven weeks were complete and full (תמימות), then the person will be a changed and we will have a new entity at the conclusion. We count seven weeks but if they are full then we will have a new creation at the end and with the addition of that one there will be fifty.