What is the ruling if a bequest is made of a fraction of several identical items (e.g., one-third of three slaves), and some perish or are rightfully claimed by others?

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If one-third of three slaves is bequeathed, and two slaves perish or are rightfully claimed by others, the legatee receives only one-third of the remaining slave. Al-Shafi'i and the proponents of opinion hold this view because the bequest did not specify more than three parts from the remainder, as the legatee was initially made a partner with the heirs in the entitlement.