The parable of the Net (13,47-48) its interpretation (13,49-50) and the parable of the householder (13, 51-52) are found only in the Gospel of Matthew.
In the parable of the Net, a large net is used to catch fish of every kind. There is no sorting out of the fish at the time of their being caught. It is only after the net is full and drawn ashore that the sorting takes place. The good fish are kept and the bad are thrown away.
The interpretation focuses on the fate of the evil (bad fish), which will be thrown into the furnace of fire. It does not speak about the fate of the righteous except to say that the evil will be separated from them.
In the parable of the householder, both the new and old are affirmed. However, the old, which is valuable, is presented in a new light and therefore seen in a new way. The fact that the order of the words is “new” and “old” is an indication that the new is to be used to interpret the old and not the other way around.