Musannaf Ibn Abi Shayba 7:277

Ubaydah ibn Humayd narrated to us, from Mansur, from Ibrahim, regarding a man upon whom there is a vow to walk to the House (the Kaaba), and he walks, then he becomes exhausted. He said: He may ride. Then, when the following year comes, he shall ride what he walked, and walk what he rode.