It is narrated from Sayyiduna Abu Sa'id al-Khudri and Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that they were with him (peace and blessings be upon him) on a journey: the one fasting would fast and the one not fasting would break his fast, but no fasting person found fault with one not fasting, nor did one not fasting find fault with a fasting person.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8164