Not graded
Riyad as-Salihin 1279
وعنه أن امرأة قالت: يا رسول الله إن فريضة الله على عباده في الحج، أدركت أبي شيخًا كبيرًا، لا يثبت على الراحلة، أفأحج عنه؟ قال:
"نعم"
Ibn 'Abbas (May Allah be pleased with them) reported:
A woman came to the Messenger of Allah (ﷺ) and said, "Allah's obligation upon His slaves has become obligatory on my father in his old age. My father is very old and incapable of riding. May I perform Hajj on his behalf?" He (ﷺ) said, "Yes."
[Al-Bukhari and Muslim].
Cited in Riyad as-Salihin (No. 1279).