Near Bethany, Jesus lifts up his hands and blesses the disciples. The physical gesture belongs to a long biblical tradition in which raised or extended hands accompany blessing and prayer.
Luke therefore depicts Jesus' final action toward his followers in the posture of one bestowing blessing.
Priestly blessing in the Hebrew Scriptures is associated with formally pronouncing God's favor upon the people, and raised hands appear in biblical prayer and blessing contexts. The gesture itself was intelligible without requiring that Luke identify Jesus' blessing with one particular liturgical formula.
Luke says that Jesus departs while blessing them, making the blessing an ongoing action at the moment of separation.
The cultural gesture shapes the emotional meaning of Jesus' departure. His final visible posture is not one of abandonment or rebuke but of blessing.
This helps explain Luke's surprising conclusion: the disciples do not return to Jerusalem grieving. They return with great joy, worshiping and awaiting what Jesus has promised.