Nasai

821. Commentary: For men, the first row is the best in every respect because the first row is superior and also farther from the women. "Best" here means the one with the greatest reward. The last row of men, in terms of reward and rank, is lesser in reward, and if it is closer to the women, then an additional deficiency arises, because the proximity of men and women leads to distraction from prayer and causes temptation (fitnah). The first row of women being the worst and the last row being the best is in the case when they are standing behind the men. If they are separate from the men, then this distinction does not apply. In general, the most virtuous prayer for a woman is in her home. However, if Allah ta‘ala makes a woman's prayer in the mosque in congregation better or equal to her prayer at home, then this is not impossible, but in light of the apparent text, we will say that a woman's prayer is best in her home, except in the case where, in addition to congregational prayer, there is also an arrangement for educational and training gatherings in the mosque. In that case, it is possible that the woman coming for this purpose attains superiority. And Allah knows best.

Hadith Commentary: Benefits and Issues:
"Those upon whom Allah and you have bestowed favor" refers to:
Your (sallallahu alayhi wa sallam) adopted son, Hazrat Zayd ibn Harithah (radi Allahu anhu).
You (sallallahu alayhi wa sallam) married him to your paternal cousin, Hazrat Zaynab bint Jahsh (radi Allahu anha),
who was extremely beautiful and graceful,
and, being of Qurayshi lineage, was not inclined toward this marriage.
Allah, the Exalted, made the decision of His Messenger final,
because of which she became content,
but due to her beauty and the nobility of her lineage,
she did not give Hazrat Zayd (radi Allahu anhu) the importance he deserved as a husband,
and so there were frequent arguments and disputes between husband and wife.
Hazrat Zayd (radi Allahu anhu) had reached the conclusion
that it was not possible for him to continue with her,
and therefore he should divorce her.
For this, Hazrat Zayd (radi Allahu anhu) consulted you (sallallahu alayhi wa sallam).
Just as Allah, the Exalted, through Hazrat Zayd (radi Allahu anhu), abolished the custom and ignorance of adoption,
whereby an adopted son was considered as a real son,
He also intended to abolish the ignorant custom that the wife of an adopted son could not be married,
and informed His Messenger (sallallahu alayhi wa sallam) that Hazrat Zayd (radi Allahu anhu) would divorce his wife,
and you (sallallahu alayhi wa sallam) would marry her.
The Messenger of Allah (sallallahu alayhi wa sallam) feared
that if he married Zaynab (radi Allahu anha),
the disbelievers and hypocrites would seize the opportunity to launch a storm of criticism against him.
People would say:
What kind of Prophet is this,
who married the wife of his adopted son and his own daughter-in-law?
Therefore, you (sallallahu alayhi wa sallam) wished
that Hazrat Zayd (radi Allahu anhu) would not divorce her,
so that the occasion for your marriage would not arise.
But since you (sallallahu alayhi wa sallam) are the final Messenger,
if this issue was not resolved in your Shariah,
then this custom could never have been abolished until the Day of Judgment.
Therefore, the wisdom of Allah, the Exalted, required that Hazrat Zayd (radi Allahu anhu) divorce his wife,
and the Prophet (sallallahu alayhi wa sallam) marry her,
and that your action would serve as proof and evidence for the Muslims
that an adopted son,
just as he is not a real son,
likewise, his wife is not a real daughter-in-law,
such that marriage to her would be prohibited.
Note:
To deduce from this incident
that the Prophet (sallallahu alayhi wa sallam) possessed knowledge of the unseen (ilm al-ghayb),
because he knew what would ultimately happen, is not correct,
because if he knew the outcome,
then why did he (sallallahu alayhi wa sallam) prevent Hazrat Zayd (radi Allahu anhu) from divorcing her? And why did he fear the criticism of the people? Likewise, the obedience to the command and decision of the Prophet (sallallahu alayhi wa sallam) is obligatory,
but this does not mean that he is the owner and disposer of the lives and wealth of his followers.
If this were the case, then when Hazrat Barirah (radi Allahu anha) was told by the Prophet (sallallahu alayhi wa sallam) to remain in the marriage of Hazrat Mughith (radi Allahu anhu),
he did not say:
"This is my advice, and it is up to you whether you accept it or not."
She replied: If it is your command and decision, then it is upon my head and eyes (i.e., I will obey),
but if it is advice, then I cannot remain with Mughith (radi Allahu anhu).
Because it is not obligatory to follow the Prophet’s (sallallahu alayhi wa sallam) advice.

English Commentary:
1:
By "the first row" is meant the row that is directly connected to the imam. The meaning of "the best row is the first row" is that, compared to the other rows, there is more goodness and virtue in it, because those who are in the row closest to the imam benefit directly from the imam,
they listen to the recitation of the Qur’an and the takbirs,
and, being far from the women, they are protected from the whisperings and evil thoughts that disturb the prayer,
and the meaning of "the last row is the worst row" is that there is less goodness and virtue in it compared to the other rows;
it does not mean that those who are in it are evil.

2:
The last row of the women is better because it is farther from the men, and thus the women participating in this row are protected from the whisperings of Satan and from temptations.

3:
This ruling applies in the case when the rows of men and women are arranged one behind the other;
if the women are praying separately from the men, then their first row will be the best.

678. Commentary:
For men, it is desirable to go outside the home for prayers and other affairs of life; therefore, for them, securing a place in the first row and spending as much time as possible in the mosque is a cause of reward and virtue. And whoever comes later, his rank keeps decreasing accordingly. However, for women, it is more virtuous and superior that they remain in their homes. Nevertheless, it is permissible for them to come to the mosque for prayer, so the woman who leaves her house exactly at the prayer time and spends the least amount of time outside her home—and thus finds a place in the last rows—is superior to the woman who comes earlier, secures a place in the first row, and spends more time outside her home. Furthermore, the last row of men is closer to the women, and the first row of women is closer to the men. For this reason, these two rows have been considered of lesser rank, whereas the first row of men and the last row of women are farther from each other, and there is no fear of distraction or disturbance there; thus, their reward is greater. Nowadays, with the proper arrangements of partitions and separate sections for men and women during prayer, the possibility of such distraction is also greatly reduced.

Benefits and Issues:
➊ The best row refers to that row in which the reward is the greatest. And the most inferior row refers to that row in which the reward is the least. However, reward is present in that as well.

➋ The wisdom behind the last rows of women being superior is that they are farther from mixing with men. For this very reason, a woman’s prayer in her home is superior to her prayer in the mosque.

Benefit:
In this hadith, the best row for women is described as the last row, and the best row for men is described as the first row. From this, it is also understood that women may perform congregational prayer in the mosque; the rows of men will be behind the imam, and then behind the men, the women will form their rows.