From The Explanation of the Gospel of St. John by Blessed Theophylact, Archbishop of Ochrid and Bulgaria
It is fitting that He grants joy to the women, condemned to bear children in pain and suffering; and peace to the men, on account of the warfare that would engulf them for preaching the Gospel. At the same time He reveals that the cross has ushered in peace: “The cross has brought peace: now I send you forth to proclaim it.” To strengthen and embolden the disciples, He declares, “As My Father hath sent Me, even so send I you. It is My work you have undertaken, so do it boldly: I will be with you.” Behold the authority of his command: “It is I Who sends you (̓Εγὼ πέμπω ὑμᾶς).” No longer does He condescend to the limitations of their understanding, saying as He often did before the resurrection, “I will ask My Father and He will send you.” Now He breathes on them and gives them the Holy Spirit—but not the entirety of the gift He would bestow at Pentecost. Receive ye the Holy Spirit, means, “Let this partial bestowal of grace make you ready to receive later the fullness of the Holy Spirit.” The words, Whose soever sins ye remit, they are remitted unto them, indicate the particular gift He gives the disciples now: power to forgive sins. Later, on Pentecost, the Holy Spirit Himself would descend in all His might, lavishing upon the apostles every spiritual gift and power to work wondrous deeds, such as raising the dead.