Midrasch zu Tehillim 61:7

"For thou, O Lord, hast made me glad through thy work" (Ps. 92:4). Adam said: The Holy One, blessed be He, had made me glad and brought me into the garden of Eden, and showed me the place of the abode of the righteous in the garden of Eden, and He showed me the four kingdoms, their rule and their destruction; and He showed me David, the son of Jesse, and his dominion in the future that is to come. I took from my years seventy years and added them to his days, as it is said, "Thou wilt add days to the days of the king; his years shall be as many generations" (Ps. 61:6). The Holy One, blessed be He, said to him: Thou wilt add days to the days of (the king Messiah); I also will add to his years in the future which is to come, as though they were many generations, as it is said, "His years shall be as many generations" (ibid.). I have given to God praise, and song (lauding) His works, as it is said, "I will sing of the works of thy hands" (Ps. 92:4).