Ps 89:4

“"For a thousand years in Your sight are but as yesterday, which is past by" [Psalm 90:4]: hence we ought to turn to Your refuge, where You are without any change, from the fleeting scenes around us; since however long a time may be wished for for this life, "a thousand years in Your sight are but as yesterday:" not as tomorrow, which is to come: for all limited periods of time are reckoned as having already passed. Hence the Apostle's choice is rather to aim at what is before, [Philippians 3:13] that is, to desire things eternal, and to forget things behind, by which temporal matters should be understood. But that no one may imagine a thousand years are reckoned by God as one day, as if with God days were so long, when this is only said in contempt of the extent of time: he adds, "and as a watch in the night:" which only lasts three hours. Nevertheless men have ventured to assert their knowledge of times, to the pretenders to which our Lord said, "It is not for you to know the times or seasons, which the Father has put in His own power:" [Acts 1:7] and they allege that this period may be defined six thousand years, as of six days. Nor have they heeded the words, "are but as one day which is past by:" for, when this was uttered, not a thousand years only had passed, and the expression, "as a watch in the night," ought to have warned them that they might not be deceived by the uncertainty of the seasons: for even if the six first days in which God finished His works seemed to give some plausibility to their opinion, six watches, which amount to eighteen hours, will not consist with that opinion.”

“For a thousand years are in Your eyes A thousand years of man are like one day of the Holy One, blessed be He, and part of the night with it; for one day of the Holy One, blessed He, and a little of the night of the Holy One, blessed be He, are a thousand years, for the text does not say that the day of the Holy One, blessed be He, is like a thousand years, but that when a little of the night elapses with it, then His day is complete, and it is a thousand years. Therefore, Adam died within a thousand [years] for had he lived a thousand [years] it would be more than the day of the Holy One, blessed be He. Perhaps the amount of that watch equals the time from the death of Adam until a thousand years, but we do not know how much that watch was, except from conjecture. I found [this]: For a thousand years are in Your eyes, etc. And when repentance came into Your thoughts from the beginning, You judged well and created it. Now those years were appropriate for it because people’s days were many, so that a thousand years were in Your eyes like one passing day, which passed and was gone, with a little of the night with it, for You said to Adam (Gen. 2:17): “for on the day you eat of it, you will surely die,” and he lived nine hundred and thirty years. We find that a thousand years equal one whole day and a little of the night with it. like yesterday, which passed Which already passed.”