The Feast of Ascension is the fortieth day after Resurrection Sunday, commemorating the Ascension of Christ into heaven, according to Mark 16:19, Luke 24:51, and Acts 1:2. The word Ascension in Greek (analeptics) means, “lifting up.” It is the event that signifies Christ ascending to heaven to be seated at the right hand of God the Father in power and glory, completing the plan of salvation. Generally speaking, in Orthodoxy, the greater emphasize is on "the death, burial and resurrection of Jesus Christ," leaving the Ascension with lesser importance within the minds of the faithful. This is only natural, since the hard work of fasting and extensive praying ends with the Feast of the Resurrection. Nevertheless, as stated earlier, it is the Ascension that completes the plan of salvation; and therefore, for the Church, it is of equal importance.
https://stlukemission.org/sermons/2017/5/29/jesus-christ-the-king-sermon-on-the-ascension