It is narrated from Sayyiduna Ka'b bin Asim (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Fasting during travel is not an act of righteousness." Imam Hasan did not attribute this narration to Sayyiduna Ka'b (may Allah be pleased with him), nor did Janab Makhzumi call him "Ash'ari." I have mentioned these words in Kitab al-Kabir.