When Amir al-mu'minin decided to march towards Syria (ash-Sham) he spoke these words:
My Allah, I seek Thy protection from the hardships of journey, from the grief of returning and from the scene of devastation of property and men. O' Allah, Thou art the companion in journey and Thou art one who is left behind for (protection of the) family. None except Thee can join these two because one who is left behind cannot be a companion in journey nor one who is in company on a journey can at the same time be left behind.
as-Sayyid ar-Radi says: The earlier part of this sermon is related from the Prophet but Amir al-mu'minin has completed it very aptly by adding most eloquent sentences at the end. This addition is from "None except Thee can join" upto the end.