Ibn Tamiyah provided shelter to his enemy al Bakri who did his takfeer

Ibn Taymiyah who gave shelter to his enemy Noor ud din Ali al Bakri who said Ibn Taymiyah is a Kaafir and should be persecuted. Al-Bakri issued a Fatwah declaring that Ibn Taymiyyah was a Kāfir as Ibn Taymiyah refuted him on the issue of Istigatha through dead. Due to his takfeer against Ibn Taymiyah he was stopped to give fatwah by the state.  Ibn Taymiyah was so generous that he defended him in front of the state and provided al Bakri shelter in Egypt when they were in search of him. May Allah reward him how good was he against his enemies.

Ibn Kathir said al-Bakri was stopped to give fatwa and thrown out from the city.
وذلك لاجترائه وتسرعه على التكفير والقتل والجهل الحامل له على هذا وغيره.
This was because he dared to (give fatawa on) takfeer and killing (i.e. Ibn Taymiyah) very early and his ignorance was the reason behind this. [AlBidaya wal Nihaya vol 14 page 89]

Sayed Husayn Hasani writes:
“When sultan became angry with al Bakri, He ordered to cut his tongue. Ibn Taymiyyah went to Sultan and requested him to forgive him. He was forgiven but al Bakri was stopped to give fatwa.” [Sahib as-Sayf wal Qalam Ibn Taymiyyah by Sayed Husayn Hasani page 61]

Ibn Kahir mentioned
وقد كان في جملة من ينكر على شيخ الاسلام ابن تيمية، أراد بعض الدولة قتله فهرب واختفى عنده كما تقدم
He is among those who are against Shykh al Islam Ibn Taymiyyah as a whole. Some of the people of power wanted to kill him. So, he ran away and took shelter from him (Ibn Taymiyyah) as it is mentioned earlier,
[Al Bidaya wal Nihaya vol 14 page 136]

Ibn Kathir also sided his teacher against him on the issue of Istigatha.

Ibn Kathir said regarding alBakri
وما مثاله إلا مثال ساقية ضعيفة كدرة لا طمت بحرا عظيما صافيا، أو رملة أرادت زوال جبل، وقد أضحك العقلاء عليه، وقد أرا السلطان قتله فشفع فيه بعض الأمراء، ثم أنكر مرة شيئا على الدولة فنفي من القاهرة إلى بلدة يقال لها: ديروط، فكان بها حتى توفي يوم الاثنين سابع ربيع الآخر، ودفن بالقرافة، وكانت جنازته مشهورة غير مشهودة،
His (al Bakri) example is like weak canal who wants to slap Pure and Great Ocean (Ibn Taymiyyah), or like the sand who wants to remove a Mountain (Ibn Taymiyyah). He made the wise people laugh at him. Sultan wanted to kill him but some of the Umaraa favoured him, Then he rejected somethings of the state and he was thrown out from al Qaahirah to the city called Dewroot. He was there untill he died on Monday 7th of Rabi ul Akhir. He was buried in Qurafa. His funereal was famous but ghayr Mahshood. [Al Bidaya wal Nihaya vol 14 page 136]

Even al Bakri`s teacher went against him due to his stance against Ibn Taymiyah.

Ibn Kathir said:
وكان شيخه ينكر عليه إنكاره على ابن تيمية، ويقول له أنت لا تحسن أن تتكلم.
His teacher used to reject him due to going against Ibn Taymiyyah. He said You do not talk good. [Al Bidaya wal Nihaya vol 14 page 136]

Ibn Kathir did Talkhees of the book of Ibn Taymiyyah “Radd al Bakri”. It is refutation of Noor al Din alBakri on the issue of Istigatha through dead. Ibn Kathir went with the opinions of Ibn Taymiyyah on the issue of Istegatha and the name of Talkhees is “Talkhees Kitab al Istegatha”.