It is narrated from Humaid that Hasan (may Allah have mercy on him) was asked: Can a person make a bequest for his wealthy brother? He said: Yes, he can, even if that brother owns twenty thousand, then he said: or owns one hundred thousand, his wealth will not deprive him of this right.
Hadith Referenceسنن دارمي / من كتاب الوصايا / 3296
Hadith Takhrijاس اثر کی سند صحیح ہے۔ دیکھئے: [سنن سعيد بن منصور 378 من طريق هشيم، قال: أخبرنا حميد الطويل بهذا الإسناد]
Brief Explanation
(Commentary on Hadith 3295)
It is understood from this that a bequest (wasiyyah) can be made for any non-heir person, even if the heir is wealthy. And that non-heir may receive the wealth from the bequest, even if he is wealthy.