The Joy of Receiving a Gift from Hashem

The Tiferes Shlomo translates the pasuk to mean that one will rejoice because he received a gift from Hashem. He compares this to when a person receives a gift from a king. In addition to being overjoyed with the gift itself, one is even more happy and proud about the fact that the king deemed him fitting to receive a gift. So too, when Hashem provides for us, in addition to being with what He gives us, we should be delighted and proud that the King chose to give us a present.