Why is it recommended to close the gaps and straighten the rows in prayer, despite the existence of hadiths that command it? And is there a consensus on it being recommended? And is it permissible to spread one's feet apart to achieve this if we say it is obligatory?

Authentic hadiths indicate the obligation of straightening rows, and a consensus has been reported regarding its desirability. It is desirable to space one's feet about a handspan apart while standing. If a space remains between worshippers after spreading out by about a handspan, the worshipper should hold the hand of the person next to them or signal to them to fill the gap, because the Prophet, peace and blessings be upon him, said: "Straighten your rows, align your shoulders, fill the gaps, be gentle with the hands of your brothers, and do not leave any openings for Satan. Whoever joins a row, Allah will join him, and whoever cuts a row, Allah will cut him off." It is not required to space the feet more than what is prescribed by Sacred Law, as doing so would disrupt the posture of the prayer.