Matthew 9:16-17

9:16 No one sews a patch of unshrunk cloth on an old garment, because the patch will pull away from the garment and the tear will be worse. 9:17 And no one pours new wine into old wineskins; 1  otherwise the skins burst and the wine is spilled out and the skins are destroyed. Instead they put new wine into new wineskins 2  and both are preserved.”

1 sn Wineskins were bags made of skin or leather, used for storing wine in NT times. As the new wine fermented and expanded, it would stretch the new wineskins. Putting new (unfermented) wine in old wineskins, which had already been stretched, would result in the bursting of the wineskins.

2 sn The meaning of the saying new wine into new wineskins is that the presence and teaching of Jesus was something new and signaled the passing of the old. It could not be confined within the old religion of Judaism, but involved the inauguration and consummation of the kingdom of God.