In Judaism, the covenant between God and Israel has two aspects to it—a concrete contract, on the one hand, and an infinite set of aspirations, on the other.
Thus, the 613 mitzvot are concrete obligations that the Jewish people take upon themselves in serving God, but in and of themselves they do not exhaust our commitments and obligations, because a relationship rooted in love can never be encapsulated in a checklist, no matter how long or detailed. Love’s aspirations are limitless, and hence the Bible mandates not only that we observe the commandments, but also that we “walk in God’s ways,” which our sages interpret as living a life of chesed, of love manifested as kindness. The concrete mitzvot thus represent the baseline commitment beneath which we may not fall; a life of lovingkindness is the height towards which we aspire.