Musar su Salmi 21:5

We are told in the Zohar Parshat Vayishlach (Sullam edition page 16), that Jacob and Joseph jointly donated 70 years of their lives to David. The Zohar writes as follows: David, [though extant in concept] had not been allocated any life on earth at all. When Adam saw this he donated 70 years of his life to David. This is why he did not live to be the 1000 years he was entitled to, but died at 930. The first 1000 years of human life may be understood as a combination of the lives of Adam and David. Rabbi Shimon continued to expound on Psalms 21,5: חיים שאל ממך, נתתה לו ארך ימים עולם ועד. "He asked You for life; You granted it; a long life everlasting." The first part of the verse applies to king David who, when his soul was created and placed in גן עדן, saw that no lifespan on earth had been allocated to him. As soon as Adam was created, he concluded that Adam's life was the answer to his prayer. Rabbi Shimon added that each one of the patriarchs also donated a portion of their designated lifespans to David. Abraham contributed, so did Jacob, and so did Joseph. Isaac did not give up any part of his life on earth in favor of David. The reason is because David "was from his side," בא מצדו.