Short answer. Yes, but only within strict limits. The Civil Code recognises this arrangement — a fideicommissary substitution — provided the substitution does not go beyond one degree from the first heir, and both the first and the second heir are alive when the testator dies.
What the law says
A fideicommissary substitution by virtue of which the fiduciary or first heir instituted is entrusted with the obligation to preserve and to transmit to a second heir the whole or part of the inheritance, shall be valid and shall take effect, provided such substitution does not go beyond one degree from the heir originally instituted, and provided further, that the fiduciary or first heir and the second heir are living at the time of the death of the testator.
Civil Code, Article 863 — Fideicommissary Substitution. Read the full provision →
What the arrangement is called and how it works
The Code's name for it is a fideicommissary substitution. The will gives the property to a first heir — the fiduciary — who is entrusted with the obligation to preserve and to transmit to a second heir the whole or part of the inheritance. Your brother would not be a caretaker or a trustee in the ordinary sense; he inherits, and he enjoys the land, but he holds it subject to a duty that runs with it. When the time fixed by the will arrives, or on his death if the will says so, the property must pass intact to the person your father named. He cannot consume it, and he cannot leave it to his own choice of successor.
The two conditions that decide whether the clause survives
Article 863 makes the substitution valid only provided such substitution does not go beyond one degree from the heir originally instituted, and provided further, that the fiduciary or first heir and the second heir are living at the time of the death of the testator. The one-degree limit stops a testator from controlling the property through generation after generation; a chain of successive heirs stretching into the future is not what the law permits. The second requirement is unforgiving on timing — the second heir must already be alive when the testator dies. A grandchild not yet born at that moment cannot be the second heir under this article, however clearly the will names him.
The limit that overrides everything: the legitime
A fideicommissary substitution cannot be laid on the legitime. Compulsory heirs — children, in most families — are entitled by law to a fixed share of the estate, and that share must come to them free of conditions, burdens and substitutions. So a father may impose this arrangement on the free portion he is entitled to dispose of, but he cannot use it to tie up what the law already reserves to his children. The first question in any real case is therefore arithmetic before it is interpretation: how large is the legitime, what is left as the free portion, and does the land in question fit inside it?
What to do with a will like this in hand
Do not act on the clause, and do not sell or mortgage the land, until the will has gone through probate — a will has no operative effect in the Philippines until a court allows it. Have counsel read the exact wording, because a direction to "keep and later give" is treated very differently from a simple gift with a wish attached, and a clause that merely expresses a hope imposes no obligation at all. If any of the article's requirements is missing, the substitution can be void while the institution of the first heir stands, which changes who owns the land outright. Bring the will, the title, the death certificate and a list of the compulsory heirs to that first meeting.