en su testamento

in their will

→ en
phrase Rare #52,000
in their will “Su” can mean his, her, or their, depending on context.
SP: En su testamento, dejó sus libros a su hermana.
EN: In their will, they left their books to their sister.

Dejó todas sus propiedades a su mujer en su testamento.

He left all his property to his wife in his will.

Él le dejó todo a ella en su testamento.

He left everything to her in his will.

Su padre le dejó la casa en su testamento.

His father left him the house in his will.

Hubo una disposición en su testamento para su amante.

There was a provision in his will for his lover.