It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that during the blessed era of the Prophet Muhammad (peace and blessings be upon him), we used to drink water while standing and eat food while walking (because, due to the preoccupation with jihad, where was there time for eating and drinking?).
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 4765
Hadith Gradingحکم دارالسلام:إسناده ضعيف، أبو البزري مجهول