As for the men, the further forward they stand, the more excellent their row. The Prophet (peace and blessings be upon him) cautioned against lagging behind, saying, “People will keep holding back until Allah holds them back.” This is a grave matter: whenever a person avoids the first, second, or even third row, Allah casts into his heart a preference for staying behind in every good deed—may Allah protect us. Hence his statement, “People will continue to hold back until Allah holds them back.” My brother, strive for the very first row, then the one after it.
The Prophet’s words, “The best rows for women are the last and the worst are the first,” apply so long as the women are praying in the same area as the men. If, however, the women have their own designated space, then their best rows are the first, for they are closest to the imam and no objectionable mixing occurs, since they are far from the men.
The narrator further mentioned that the Prophet (peace and blessings be upon him) used to straighten his Companions’ shoulders at the opening takbīr (saying “Allahu akbar”), aligning their shoulders—that is, their upper arms—and saying, “Stand straight and do not differ, lest your hearts differ.” In other words, when some worshippers are forward and others are backward, that outward unevenness breeds discord in their hearts.
In the last of the cited ahadith, the Messenger of Allah (peace and blessings be upon him) ordered that the rows be made straight, declaring, “Straightening the rows is part of perfecting the prayer,” and indeed it is. Another narration has, “Establishing the rows is part of perfecting the prayer.”
Therefore we should arrange our rows properly, completing them in order—first row, then the next—and closing all gaps, so that our prayer may be complete. Allah is the One who grants success.