(Canto 1, line 1)
"The midway upon the journey" of a man's life is 35 years. The Bible verse Psalms 90:10 reads: "The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labour and sorrow; for it is soon cut off, and we fly away." In another of his works, the Convivio, Dante says himself that a person's life can be likened to an arc. Speaking of the high point of the arc, he writes: "My own view is that in most people it occurs somewhere between the ages of thirty and forty. I also believe that in those endowed with a perfect nature it occurs in the thirty-fifth year." (Treatise 4, chapter 23) His view was that the high point of Jesus' life occurred exactly in his thirty-fifth year.
It is perhaps fitting with Dante's temperament for him to view himself as "endowed with a perfect nature". Commentators believe that Dante was born around 1265, and that his journey through hell might have occurred in the year 1300, that is to say, exactly when he was in 35 years old. The date is supposed to have been on Good Friday that year, that is, April 8.