Parshas Chayei Sarah 5787
והמלך דוד זקן בא בימים … (מלכים א' א,א-לא)
The great Rabbeinu Saadia Gaon zt”l was once in a town anonymously, where a member of the community recognized that he was not just an ordinary person, but rather a true Talmid Chacham. He invited him into his home and treated him with tremendous respect. During their conversation, the host discovered the true identity of his illustrious guest, and immediately fell to the ground begging the great Gaon for forgiveness. However, Rabbeinu Saadia could not understand; he had been treated with great respect. Why was there a need to ask for forgiveness? His host responded that in truth, had he known that his guest was the great Rabbeinu Saadia Gaon, he would have treated him with even greater respect.
Rabbeinu Saadia later explained, that with each passing day, a true Tzaddik expands his spiritual growth, therefore each day he is constantly doing Teshuva for the fact that the previous day’s actions were not on the same level as the present day's.
The Zohar zt"l writes that both Avraham Avinu in the Parsha and Dovid Hamelech in the Haftorah, were elderly men who had “come to their days.” At the times of their deaths, they had both reached a point of near perfection, however, since a Tzaddik never feels content with his spiritual achievements and is always striving for more, one would think that they left the world with an unfinished agenda. Therefore, the Torah tells us that Avraham and Dovid “came to their days”, alluding to the fact that they both were Tzaddikim in the fullest meaning of the word, and had completed their purpose in life.