The ruling on using markers for prayer rows to straighten them

Question:
Is tying belts in the mosques for the purpose of straightening the rows part of the Sunnah, or what is it?

Answer:
I do not know of any evidence indicating that it is part of the Sunnah, nor do I know of any Shari'ah text indicating that it is prohibited. We are commanded to straighten the rows and not let them be crooked. If some people use something to help regulate the row, keep it straight, and prevent people from moving forward or backward, I hope there is nothing wrong with that. However, it cannot be called a Sunnah; I do not know of that.
The Sunnah is to take care of straightening the rows, to command them to be even, and to command them not to move ahead of one another. The Messenger of Allah (peace and blessings be upon him) used to command them to do so before he said the takbir. He would command them and take care of them until they were straight. If some people place mats according to the length of the row... so that the row is even, or place strings... I do not know of any harm in that.