Yahya related to me from Malik that Urwa ibn Udhayna al-Laythisaid, "I went out with my grandmother who had vowed to walk to theHouse of Allah. When we had gone part of the way, she could not go on.I sent one of her mawlas to question Abdullah ibn Umar and I went withhim. He asked Abdullah ibn Umar, and Abdullah ibn Umar said to him,'Take her and let her ride, and when she has the strength let her rideback, and start to walk from the place from which she was unable to goon.'~Yahya said that he had heard Malik say, "I think thatshe must sacrifice an animal."Yahya related to me from Malikthat he had heard that Said ibn al-Musayyab and Abu Salama ibn Abd ar-Rahman said the same as Abdullah ibn Umar.
USC-MSA web (English) reference: Book 22, Hadith 4
Arabic reference: Book 22, Hadith 1015