Sunni Islam [whether the claimants be Sufi or Wahhabi] both agree that al-Hafiz Ibn Katheer is a renewer of Islam [Ar. Mujaddid], one who has been sent by Allah to confirm the truth and enjoin the Sunnah, and refute the innovations that have appeared amongst the Muslims.
In the work al-Bidayah wa an-Nihiyah, also known more commonly as Tareekh Ibn Katheer [i.e. History of Islam compiled by Ibn Kathir], not only has he wrote a whole chapter dedicated to the Mawlid [translated into English by Bilal Patel under the title Mawlid, The Blessed Birth, TURATH PUBLISHING], but he has made explicit statements that can only be taken and understood to be in favour of the Mawlid.
The first quote is from the above mentioned book taken from the collection al-Bidayah wan-Nihayah:
“The Night of the Prophet’s birth is a magnificent, noble, blessed and holy night, a night of bliss for the believers, pure, radiant with lights, and of immeasurable price.” [Ibn Kathir, Mawlid Rasul Allah]
In another part, he points out is that the only person found to be complaining about the Mawlid of the Messenger of Allah was the Shaytaan:
أن إبليس رن أربع رنات حين لعن وحين أهبط وحين ولد رسول الله صلى الله عليه وسلم وحين أنزلت الفاتحة
Translation: Iblis cried loudly four times, first when Allah declared him as cursed, second when he was thrown out, Third When Prophet (sal Allahu alayhi wasallam) was born and fourth when Surah al-Fatiha was revealed [Ibn Kathir in Al Bidayah wan-Nihayah, Volume No. 2, Page No. 166] [scan needed]
Ibn Kathir also mentions that when the Prophet sal Allahu alaihi wasallam was born, Abu Lahab showed a great expression of joy and freed a slave by waving his finger
“When Abu Lahab died, someone from his household saw him in a dream, they asked him what happened in the grave he said ‘I am being punished severely, but on Mondays, I get water from my finger with which I freed Thuwayba” [Sahih Bukhari, Ibn Kathir Sirat al-Nabi svol 1, pg. 124 & Mawlid un-Nabi sallAllahu alaihi wasallam pg. 21 & Arabic al-Bidaya pg. 272-272] [scan needed]
In another instance, he writes not only the words of praise for a practitioner of the Mawlid, but yet even shows his respect when writing about the Mawlid as to be al-Mawlid ash-Shareef. Something that is impossible of the statements of the objectors. The following can only demonstrate that Ibn Kathir was indeed of al-Mawlid ash-Shareef.
He says regarding Shah Malik al-Muzzafar (Rahimahullah) the brother in law of Salah-ud-din Ayyubi (Rahimahullah) the great warrior of Islam respected by all. Regarding this great personality the Salafis spread deception by forging words of Ibn Kathir (Rahimahullah) i.e. he was actually a Fasiq, cruel and Bidati ruler (Naudhobillah) but in reality Imam Ibn Kathir (Rahimahullah) said this:
أحد الاجواد والسادات الكبراء والملوك الامجاد له آثار حسنة وقد عمر الجامع المظفري بسفح قاسيون وكان قدهم بسياقه الماء إليه من ماء بذيرة فمنعه المعظم من ذلك واعتل بأنه قد يمر على مقابر المسلمين بالسفوح وكان يعمل المولد الشريف في ربيع الاول ويحتفل به احتفالا هائلا وكان مع ذلك شهما شجاعا فاتكا بطلا عاقلا عالما عادلا رحمه الله وأكرم مثواه وقد صنف الشيخ أبو الخطاب ابن دحية له مجلدا في المولد النبوي سماه التنوير في مولد البشير النذير فأجازه على ذلك بألف دينار وقد طالت مدته في الملك في زمان الدولة الصلاحية وقد كان محاصر عكا وإلى هذه السنة محمودالسيرة والسريرة قال السبط حكى بعض من حضر سماط المظفر في بعض الموالد كان يمد في ذلك السماط خمسة آلاف راس مشوى وعشرة آلاف دجاجة ومائة ألف زبدية وثلاثين ألف صحن حلوى
Translation: He was a generous, mighty master, and glorious ruler, whose works were very good.He built Jamiya al Muzaffari near Qasiyun… During Rabi ul Awwal he used to celebrate Mawlid ash Shareef (يعمل المولد الشريف في ربيع الاول) with great celebration, Moreover, he was benevolent, brave, wise, a scholar, and just person – Rahimuhullah wa Ikraam – Sheikh Abul Khattab (Rahimahullah) wrote a book on Mawlid an Nabwi for him and named it At-Tanwir fi Mawlid al Bashir al Nazeer, for which he gave him 1000 dinars. His rule stayed till the Rule of Salahiya and he captured Aka and he remained a man worthy of respect.
Al-Sabt mentions that a person attending the gathering of Mawlid held by Muzzafar said: He used to fill the table with 5000 well cooked goats, 10,000 chickens, 100-thousand bowls (of milk) and 30,000 trays of sweets.
[Tarikh Ibn Kathir, Al Bidayah Wan Nihaya Volume 13, Page No. 174]