Bukhari

Hadith Commentary:
➊
The example mentioned in this hadith is to explain the issue of the finality of prophethood, so that it becomes firmly established in the mind that the edifice of prophethood was completed with the blessed arrival of the Messenger of Allah (sallallahu alayhi wa sallam), even though many have arisen attempting to breach it.
In the Indian subcontinent, the British agents and their fostered servant, Ghulam Ahmad Qadiani, also claimed prophethood.
May Allah grant our elders immense reward in His presence; they gave a crushing response to him during his lifetime.
The services of Maulana Muhammad Husain Batalwi and the Lion of Punjab, Maulana Thanaullah Amritsari (rahimahullah), are truly unforgettable.
For the issue of the finality of prophethood, the study of Maulana Muhammad Abdullah Mi‘mar Amritsari’s work “Muhammadiyah Pocket Book in Response to Ahmadiyah Pocket Book,” published by Maktabah Salafiyyah Lahore, will be very beneficial.

➋
It should be clear that the brick was placed in a corner of the building, which means that this brick does not have a foundational status for the building such that, without it, the building would not exist at all; rather, with this brick, the beauty of the building was enhanced.
It absolutely does not mean that the building was deficient without it, because every prophet’s law (shari‘ah) was perfect for its own time.
The purpose is that the shari‘ah of the Messenger of Allah (sallallahu alayhi wa sallam) is more complete and more excellent than all other shari‘ahs, while the shari‘ahs of the previous prophets (‘alayhim as-salam) were complete and good.
And Allah knows best.
(Fath al-Bari: 6/683)

Hadith Commentary: Benefits and Issues: The Prophet (sallallahu alayhi wa sallam) likened the entire assembly of prophets to a beautiful and most complete building, which, before his arrival, was incomplete due to the absence of a single brick, and its beauty and elegance were affected. With his arrival, the gap of that brick was filled, and through his coming, the beauty and perfection of the building were completed, and there remained no room for any other brick in the building. Now, to place any brick or pebble in it would be to blemish its beauty and elegance, which would become a cause of defect and imperfection in it, something its builder could never tolerate. Therefore, after his arrival, Allah Ta’ala does not permit any kind of prophet, because there is no longer any need for it. The building of prophethood has reached its completion. That is why he said, "Ana Khatam an-Nabiyyin"—I am the last link of prophethood; with my arrival, the edifice of prophethood has been completed.

Hadith Gloss:
Vocabulary of the Hadith:
(1)
Labinah:
Brick.
(2)
Yatufuna:
They used to circle,
they used to go around.

Explanation of the Hadith:
In the mentioned hadith, the Messenger of Allah (sallallahu alayhi wa sallam) gave his own example in relation to the prophets as that of a building, as if all the prophets are like that building from which one brick is missing at one corner. The rest of the building is complete, and just as the foundation of a building is laid, then the walls are constructed, windows and doors are installed, and the roof is placed, but the building is complete except for the deficiency of one brick at one corner. In the same way, Allah Ta’ala gradually sent prophets to perfect moral character, and sent them with guidance and knowledge to guide people towards good morals, and to complete the noble character traits, finally sent the Messenger of Allah (sallallahu alayhi wa sallam). The Messenger of Allah (sallallahu alayhi wa sallam) said in a hadith:
«بُعِثْتُ لِاُتَمِّمَ مَكَارِمَ الْاِخلَاقِ» [مؤطا امام مالك، ص: 668]
“I have been sent to perfect noble character.”
Thus, the building from which one brick was missing became complete. [ارشاد الساري: 22/6۔ بتعديل يسير]
In this hadith, there is a proof of the virtue of Muhammad, the Messenger of Allah (sallallahu alayhi wa sallam), and a proof of the finality of prophethood, that his prophethood completed the edifice of prophethood. Now, after him (sallallahu alayhi wa sallam), no prophet will come.
And from this hadith, we also learn that a person can use an example to explain a point, just as in the mentioned hadith the Messenger of Allah (sallallahu alayhi wa sallam) gave an example.

The proof of the finality of prophethood is mentioned in the Noble Qur’an:
«مَا كَانَ مُحَمَّدٌ أَبَا أَحَدٍ مِنْ رِجَالِكُمْ وَلَكِنْ رَسُولَ اللَّهِ وَخَاتَمَ النَّبِيِّينَ وَكَانَ اللَّهُ بِكُلِّ شَيْءٍ عَلِيمًا» [الاحزاب: 40]
“Muhammad (sallallahu alayhi wa sallam) is not the father of any of your men, but he is the Messenger of Allah and the Seal of the Prophets, and Allah is Knowing of all things.”
He (alayhi as-salatu was-salam) is the last prophet and will remain so until the end of the world. The descent of ‘Isa (alayhi as-salam) does not contradict the finality of prophethood because ‘Isa (alayhi as-salam) will also follow his (sallallahu alayhi wa sallam) Shari‘ah.
Until today, this is the unanimously agreed-upon belief of the entire Ummah; therefore, whoever denies the finality of prophethood is outside the fold of Islam.

Benefit:
From this blessed hadith, it is understood that the Noble Prophet sallallahu alayhi wa sallam is the final Prophet; after him, there is no need for any shadowy, representative, symbolic, or metaphorical prophet, nor will there be any prophet. And whoever makes such a claim will become a disbeliever (kafir), just as Mirza Qadiani became a disbeliever.