You need to read all of Section 50(a) for your answer:
(a) The homestead of a family, or of a single adult person, shall be, and is hereby protected from forced sale, for the payment of all debts except for:
(1)* * *
(2)* * *
(3) an owelty of partition imposed against the entirety of the property by a court order or by a written agreement of the parties to the partition, including a debt of one spouse in favor of the other spouse resulting from a division or an award of a family homestead in a divorce proceeding;
An owelty is a legal fiction. Husband and wife are divorcing so it is decided that he gets the house (homestead) and she will relocate. They have paid on the mortgage all those years and she wants to "cash out" her equity. But suppose the husband has no cash to give her. He must get a loan, but except for the owelty provision (and perhaps a home equity lien), there is no category under which he can grant a lien on the entire property to secure the cash out; it is purchase money as to her one-half, but not his one-half. Through the owelty fiction, he can place a valid lien on both halves of the property.
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