In today's gospel reading we see Jesus being asked to account for the non-compliance of His disciples on the regulation about fasting. For Jesus fasting is a sign of sorrow and mourning. In the bridegroom's presence, there should be feasting and rejoicing. Fasting is to be observed in His absence.
The early Church fasted on Wednesdays and Fridays (cf. Didache 8:1) while awaiting the parousia, the return of the bridegroom.
The two images of the garment and the wine emphasize the incompatibility between Jesus' message an the teachings of Judaism. The old garment and the old wineskin represent Judaism and the Jewish practice of piety. The new garment and the new wine represent the radical newness of Jesus' message. Thus Judaism with its act of piety cannot be accommodated in the new age of salvation which dawns with Jesus.
In the first reading we see how Rebekah and Jacob lied to Isaac to obtain the blessing and the promise which was rightfully Esaus'. Why is this so important? It is because the blessing is concerned with vitality and it cannot return or be subsequently altered. Yet, St Augustine explained that the transference of the blessing of Jacob was not a lie but a mystery which does not do justice to the pathos of the story. Jacob was a liar but he was also the bearer of the promise and the blessing. This is to fulfil the promise of salvation.
Lord, help us see You present in all events.