"For all our days have passed away in Your wrath... Rabbi Yehuda says this refers to bitterness, and the Rabbis say it refers to a youth that is cut off. We have completed our years... Our days pass away with toil and trouble...
Rabbi Chanina bar Yitzchak said even his kingdom was toil and trouble, as it says 'I will recall Rahav and Babylon...' The Rabbis say it refers to harsh shearing and afflictions. Rabbi Yudan said, nevertheless, there were good deeds in it. Who knows the strength of Your anger?
Rabbi Abba bar Kahana said, perhaps transgression has filled up your hand. Who knows the strength of Your anger? Rabbi Chanina bar Yitzchak said, whoever advances the Day of Judgment in this world, his sins come first. Let us calculate our years, so that we may bring wisdom to our hearts.
Rabbi Eliezer said, repent one day before your death. His students asked, does a man know on which day he will die? He answered, therefore, one should repent every day, lest he die tomorrow, and thus all his days will be spent in repentance. Let us calculate our years so that we may bring wisdom to our hearts.
Return, O Lord; how long will it be? Rejoice us according to the days You afflicted us, the years we have seen evil. Such are the days of the Exile in Babylonia, in Media, and in Edom. Another interpretation: such are the days of the Messiah.
How many will be the days of the Messiah? Rabbi Eliezer says, a thousand years, as it is said, 'A day that is like a thousand years.' Rabbi Yehoshua says, two thousand years, as it is said, 'For the days of our life are seventy years,' and seventy times two is one hundred and forty. And the day of the Holy One, blessed be He, is one thousand years, as it is said, 'A thousand years in Your eyes are like yesterday.'
Rabbi Baruchya says six hundred years, as it is said, 'The days of my people will be like the days of a tree.' And it is learned that this workshop is done in the earth for six hundred years. Rabbi Yosei says sixty years, as it is said, 'Before the moon, for generation of generations.'" Generation follows generation; one generation passes away, and another generation comes.
According to Rabbi Akiva, a generation is forty years, as it says, "As the days of our years, so is our life" (Psalms 90:10), which is likened to the forty years that our ancestors spent in the wilderness, as it says, "And He afflicted you, and let you hunger" (Deuteronomy 8:3). However, the Sages say that a generation is three hundred and fifty-four years, corresponding to the number of days in the lunar year, as it says, "And the year of my redemption has come" (Isaiah 63:4).
Rabbi Abbahu says that a generation is seven thousand years, corresponding to the seven days of the week, as it says, "For a young man shall marry a virgin" (Isaiah 62:5), and just as a wedding lasts seven days, so too a generation lasts seven thousand years.