Point of No Return
"Dont dare let them pause for a moment on their way to Babylon!"
This was the strange order which the Babylonian king, Nevuchadenetzer, gave to his general, Nevuzradan.
He explained that there was a danger that if these Jews on their way to Babylon had any respite for prayer and repentance their G-d was likely to accept their return to Him and thwart the Babylonian effort to exile them. Once they reached Babylon, however, the general told his soldiers to stop driving these Jewish captives and to allow them to rest. This is what is meant by the opening words of Psalm 137 in Tehillim which it is customary to say before Grace After Meals on weekdays: "By the rivers of Babylon, there we sat."
The reason he gave for allowing this rest at that point was his feeling that their repentance was less likely to be accepted by G-d outside of their holy land.