What is the ruling on straightening the rows when commencing prayer, and what are the views of the different schools of thought on this matter?

The scholars have reached a consensus on the permissibility of straightening rows in prayer, but they differed on its obligation. The majority opinion is that it is merely recommended, while the Zahiris and Imam al-Bukhari held it to be obligatory. Those who assert its obligation cite prophetic traditions, among them: "Straighten your rows, bring them close together, and align yourselves by the necks," and "Straighten your rows, for straightening the rows is part of establishing the prayer," and "You must straighten your rows, or Allah will cause discord among your faces." These hadiths indicate a command for straightening, and a command implies obligation unless there is a a deterrent that deflects it.