It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) used to remain at the very rear (of the army during a journey) so that he could urge on the weak, seat them behind him on his mount, and supplicate for them. This hadith is sahih (authentic) on the condition of Imam Muslim, but he did not record it.