This chapter collects the voluntary prayers attached to Zuhr, the units offered before and after it. The Prophet was steady with four Rak'ah before Zuhr in particular, and the reports show some variation in how the surrounding Sunnah prayers were counted and prayed.
Two ideas stand out. First, a reward is promised for guarding these prayers, protection from the Fire for the one who keeps four before and four after. Second, the Prophet explained why he loved the time just after midday, the hour when the gates of heaven open, so he longed for his good deeds to rise then. Where the wording touches finer points of how to make up a missed Sunnah, the details belong to the scholars; the heart of the chapter is steady, loving devotion.
Hadith 1113
Ibn 'Umar (May Allah be pleased with them) reported:
وعنها قالت: كان النبي صلى الله عليه وسلم يصلي في بيتي قبل الظهر أربعًا، ثم يخرج فيصلي بالناس، ثم يدخل فيصلي ركعتين، وكان يصلي بالناس المغرب ثم يدخل بيتي فيصلي ركعتين، ويصلي بالناس العشاء، ويدخل بيتي، فيصلي ركعتين. ((رواه مسلم)).
Whenever the Prophet (ﷺ) stayed in my house, he would perform four Rak'ah (supererogatory prayer) before Zuhr prayer. Then he would go out and lead Salat. He (ﷺ) would then come back and perform two Rak'ah (supererogatory prayer). He would lead the Maghrib prayer and come back and perform two Rak'ah (supererogatory prayer). When he (ﷺ) had led the 'Isha' prayer, he would enter the house and perform two Rak'ah (supererogatory prayer). [Muslim]
In plain words
Aishah describes the Prophet's habit at home: four units before Zuhr, two after, two after Maghrib, and two after Isha, showing his steady round of voluntary prayers through the day.
Umm Habibah (May Allah be pleased with her) reported:
وعن أم حبيبة رضي الله عنها قالت: قال رسول الله صلى الله عليه وسلم: "من حافظ على أربع ركعات قبل الظهر وأربع بعدها، حرمه الله على النار" . ((رواه أبو داود، والترمذي)). وقال حديث حسن صحيح.
The Messenger of Allah (ﷺ) said, "Whoever observes the practice of performing four Rak'ah before Zuhr prayer and four after the Zuhr prayer, Allah will shield him against the Fire (of Hell). [Abu Dawud and At-Tirmidhi].
In plain words
The Prophet said that whoever keeps to four units before the Zuhr prayer and four after it, Allah will shield him from the Fire. A reward promised for guarding this practice.
'Abdullah bin As-Sa'ib (May Allah be pleased with him) reported:
وعن عبد الله بن السائب، رضي الله عنه أن رسول الله صلى الله عليه وسلم كان يصلى أربعًا بعد أن تزول الشمس قبل الظهر، وقال "إنها ساعة تفتح فيها أبواب السماء، فأحب أن يصعد لي فيها عمل صالح" ((رواه الترمذي وقال: حديث حسن)).
The Messenger of Allah (ﷺ) used to perform four Rak'ah prayer after the declining of the sun before Zuhr prayer and would say, "This is an hour at which the gates of heaven are opened, and I like that my good deeds should rise to heaven at that time." [At- Tirmidhi].
In plain words
The Prophet would pray four units after midday before the Zuhr prayer, explaining that this is an hour when the gates of heaven open, and he loved for his good deeds to rise then.
وعن عائشة رضي الله عنها أن النبي صلى الله عليه وسلم كان إذا لم يصلِ أربعًا قبل الظهر، صلاهن بعدها. ((رواه الترمذي وقال: حديث حسن)).
If the Prophet (ﷺ) could not perform four Rak'ah before Zuhr prayer, he would perform them after it (i.e., after the obligatory prayer). [At-Tirmidhi].
In plain words
If the Prophet missed the four units before the Zuhr prayer, he would make them up afterward, showing care to keep this voluntary prayer rather than simply letting it go.