The author of this monumental work in Hanbali fiqh (an explanation of the work of al-Hajjaawi, al-Iqnaa', see here) is Abu al-Sa'aadaat Mansoor bin Yoonus bin Salah al-Din bin Hasan bin Ahmad bin Alee bin Idrees al-Buhuti al-Hanbali al-Misre al-Qaahiree, he was born in 1000H, and he was of lofty character, kind and generous to the people, visiting the sick and looking after them, people would give their charity to him and he would distribute it to the students. He spent a great deal of his time in investigating the matters of jurisprudence and people would travel to him from the various horizons in order to take the madhhab of Imaam Ahmad from him. The Hanbalis of the lands of Shaam, the areas of Najd, and the lands of Maqdisiyyah, and Ba'liyyah would travel to hiim. He was also given to much worship, and was a person of much benefit (to others). His teachers include the Shaykh and Imaam Yahya bin Moosaa bin Ahmad, otherwise known as Ibn al-Hajjaawi al-Maqdisi (d. early 11th century hijrah, precisde date unknown), Shaykh Abd Allaah bin Abd al-Rahman al-Danshuri al-Shafi'i, the linguist (d. 1025H), Shaykh Muhammad bin Ahmad al-Mardawi al-Hanbali, the Shaykh of the Hanbalis of his time ((d. 1026H), al-Buhuti took most of his knowledge from him. Also the Shaykh, the Musnid, Abd al-Rahman bin Yusuf bin Ali, called Zayn al-Din bin al-Qadi (d. after 1040H). Also from his teachers were Shaykh al-Shihab Ahmad al-Waarithee al-Siddeeqee, the Shaykh al-Nur Ali al-Halabi, and al-Jamaal Yusuf al-Buhuti. He had many extensive works on Hanbali jurisprudence of which al-Qinaa' was one of the major ones. He died on Friday, 10th of Rabee al-Thaani in 1051H, after falling ill five days earlier.

Al-Buhuti wrote in this work Kashf al-Qinaa' (14/227):

(The Shaykh said: Or who hated His Messenger or what was brought by him), [meaning], the Messenger, (by agreement [of the scholars]. And he said: Or who set up between himself and Allaah intermediaries, relying upon them, invoking them and asking them, by consensus. End). Meaning, he disbelieved beacause this is like the action of the worshippers of idols, those who say, "We do not worship them except that they may bring us closer to Allaah" (39:3).

Notes

Once more we are going to repeat the exact same points and notes from previous similar articles documenting the Hanbali fiqh position on the things that expel a person from Islaam:

The first: Refutation of the claim that Shaykh Muhammad bin Abd al-Wahhaab brought a new doctrine never known before. Rather, this is what the Prophet's and Messengers came with, the call to singling out Allaah in worship and the shunning of worship besides them. When Shirk started become widespread in the Ummah and people flocked to the graves the Scholars made not of that and spoke about it, and from them, Ibn Aqil (d. 513H), Ibn al-Jawzee (d. 597H), Fakhr al-Din al-Razi (d. 606H)(see here), Ibn Taymiyyah (d. 728H), and others.

The second: This is a matter of ijmaa' (consensus) in the madhhab as corroborated by the most learned of the Hanbalite jurists of the time who were alive a century before Shaykh Muhammad bin Abd al-Wahhaab was even born, and who themselves were preceded in this takfir of the one who took others for worship besides Allaah by the likes of Ibn Aqeel (d. 513H) and Ibn al-Jawzee (d. 597H) by another three centuries.

The third: Spuriousness of the claim that Shaykh Muhammad bin Abd al-Wahhaab exited from the domain of the four madhhabs, this is plain falsehood and academic fraud.

The fourth: Exposition and unveiling of the new fake "Hanbalis", who are Ash'ari-Sufi-Mufawwidhah in reality, but who are trying to push their doctrines by wearing the cloak of Hanbali fiqh. They are actually hypocrites (in action), and the mere fact that they vilify Shaykh Muhammad bin Abd al-Wahhab and claim adherence to the Hanbali fiqh at the same time exposes them as liars and deceivers from the very outset. Claiming attachment to the Hanbali madhhab and then vilifying Shaykh Ibn Abd al-Wahhaab for declaring as Shirk the setting up of intermediaries with Allaah, calling upon them, and directing worship to them (a matter of ijmaa' in the madhhab) are two diametrically opposed affairs. It is a contradiction to claim association with the Hanbali fiqh and find fault with Shaykh Muhammad bin Abd al-Wahhaab's call to the Tawhid of the Messengers.