Ibn Abi al-Zinad narrates from his father, from the jurists of the people of Madinah whose opinion was the final word, that they used to say: Whoever bequeaths that his third be taken in the form of a garden, then that garden is endowed wherever he wished, and his heirs say: We do not permit this; he only has a right to a third of his garden, then the bequest is binding on them. The testator places his third wherever he likes from his wealth, at a fair value. The garden is just like a saddle, a sword or a garment that he bequeaths; the heirs have no right to say: He only has a right to a third of his saddle, his sword and his garment.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12594