Bukhari

Hadith Commentary:
Imam Shawkani rahimahullah states:
“The apparent meaning of this is that they used to perform the Friday prayer early in the day.” Al-Hafiz said:
“However, reconciling the narrations is preferable to claiming contradiction, and it has been established that the term ‘tabkir’ (early) is used for doing something at its earliest time or giving it precedence over something else, and this is what is meant here. The meaning is:
They used to begin the prayer before the midday rest (qaylulah), contrary to their usual practice regarding the Zuhr prayer in the heat, for they would take the midday rest and then pray, due to the legislation of delaying (ibraad) the prayer.” End quote. The ‘qaylulah’ mentioned in the hadith refers to:
Sleeping at midday.
(Nayl al-Awtar)
That is, the apparent meaning is that the noble Companions would perform the Friday prayer as the day advanced.

Hafiz Ibn Hajar rahimahullah says that it is better to reconcile both types of hadiths than to create a contradiction, and it has already been established that the word ‘tabkir’ is used for doing something at its earliest time or giving it precedence over something else, and here this is what is meant: that the noble Companions radi Allahu anhum would perform the Friday prayer at the earliest time of their daily midday rest (qaylulah), whereas in the summer their habit was to first take the midday rest to cool off and then perform the Zuhr prayer, but sometimes, contrary to their habit, they would perform the Friday prayer before the midday rest. Qaylulah refers to sleeping at midday.

In summary, the meaning and intent of these narrations is to perform the Friday prayer at its earliest time after the sun passes the zenith (zawal).

Thus, Friday prayer can be performed at both the earliest and latest times; some scholars even hold the view that Friday prayer is permissible before zawal.

However, preference is given to after zawal, and this appears to be the position of Imam Bukhari rahimahullah.

After a lengthy discussion, Mawlana Ubaidullah Sahib Shaykh al-Hadith rahimahullah states:
“And it has become clear from what we have mentioned that there is no authentic and explicit hadith regarding the Friday prayer before zawal. Thus, the preferred opinion is that of the majority. Our Shaykh said in the commentary of Tirmidhi:
‘The apparent and relied-upon view is that of the majority, that Friday prayer is not permissible except after the sun passes the zenith. As for the view of some that it is permissible before zawal, there is no explicit authentic hadith for it.’ End quote.”
(Mirqat, vol. 2, p. 203)

In summary, Friday prayer is not valid before zawal, and this view is given preference.

There is no authentic and explicit hadith regarding the validity of Friday prayer before zawal; thus, the position of the majority is correct.

(And Allah knows best what is correct)

Hadith Commentary:
(1)
The relevance of these hadiths to their chapter heading is evident, because they establish that the noble Companions (radi Allahu anhum) used to take a midday nap (qaylulah) after the Friday prayer, and would set out from their homes early for the Friday prayer. The word "tabkeer" means to hasten or do something early.
This hadith also shows that sleeping at midday is a preferred act; Allah Himself has mentioned it in the Noble Qur’an.
The Exalted says:
﴿وَحِينَ تَضَعُونَ ثِيَابَكُم مِّنَ الظَّهِيرَةِ ﴾ “And when you put off your clothes at midday (for rest).” ()
In this verse, the act of taking a midday nap (qaylulah) is mentioned.
(‘Umdat al-Qari: 5/131)
(2)
The Excellence of Conclusion! The ruling regarding the midday nap (qaylulah) had already come in the hadith of Anas, but Imam Bukhari rahimahullah narrated the hadith of Sahl radi Allahu anhu, and at its end, with the words (ثم تكون القائلة) “then there is the midday nap,” he alluded to the excellence of conclusion.
It is Imam Bukhari’s rahimahullah habit to mention, at the end of his book, a word that reminds of the Hereafter and death. Thus, it is well known that sleep is the sister of death; in this way, Imam Bukhari rahimahullah has given a reminder to be prepared for death.
May Allah the Exalted grant us success in this world and the Hereafter, and grant us a good ending upon faith.
Ameen

Benefits and Issues:
➊ The time for the midday nap (qaylulah) is at noon. However, on Fridays, the noble Companions (radi Allahu anhum ajma'in) would not rest at this time, so that they could be present for Jumu'ah at its earliest time.

➋ The same reason applies to delaying the meal until after the prayer; it is possible that they would eat after the prayer for this reason as well: that if they ate beforehand, they might become overcome by sleep during the sermon (khutbah).