Imam Ahmad bin Hanbal is one of the greatest Scholars of AhluSunnah, not only in Hadeeth, but also in Fiqh.

He had a companion by the name of Ishaq bin Mansoor al-Kosaj. Dhabi introduced him in the following manner in His Sair A’laam Nabala, 12/259

الكوسج ( خ ، م ، س ، ت ، ق ) 
الإمام الفقيه الحافظ الحجة أبو يعقوب ، إسحاق بن منصور بن بهرام المروزي

al-Kosaj, Narrator of Bukhari, Muslim, Nisai, Tirmidhi, Ibn Maja. He is Imam, Faqih, Hafiz, Hujjat…

Now, He asked Questions from Imam Ahmad and Ishaq bin Rahwia, and mentioned those in book named (  مسائل الإمام أحمد بن حنبل وإسحاق بن راهويه) Masael Imam Ahmad and Ishaq bin Rahwia.

In this book, 4/1548, He asks Imam Ahmad about Muta’a with women

[920-] قلت: لأحمد متعة2 النساء، تقول: إنه حرام؟
قال: أجتنبها أعجب3 إليّ

I asked Imam ahmad about Muta’a with Women, what do You say: it is Haram?

He said: I like to avoid it

What is very much evident from the words of Imam Ahmad is, that He did not reply: Yes it is Haram.

Rather said: I like to avoid it.

So how is this answer explained by Scholars of AhluSunnah.

Ibn Qadama Muqaddasi writes in his book, al-Mughni fi Fiqh Imam Ahmad bin Hanbal Sheebani, 7/571

وقال أبو بكر فيها رواية أخرى أنها مكروهة غير حرام لأن ابن منصور سأل أحمد عنها فقال يجتنبها أحب إلي وقال فظاهر هذا الكراهة دون التحريم

Abu Bakr Khalal says that it is Makrooh/Disliked, and not Haram/Prohibited because Ibn Mansoor asked Imam Ahmad about it, and He said: I like to avoid it. And He said: What is apparent is that it is Makrooh, and not prohibited.

Similarly, Qazi ibn-ul-Fara writes in His book, al-Masael al-Faqih min Kitab-ur-Riwayaten wa wajheen (المسائل الفقهية من كتاب الروايتين والوجهين )  in volume 2, page 107

ونقل ابن منصور أنه سأله عن متعة النساء تقول أنها حرام قال: يتجنبها أحب إليّ، فظاهر هذا أنها مكروهة وليست حراماً

Ibn Mansoor asked Him about Muta’a with women, and he said that I like to avoid it. This shows that it is Makrooh, and not Haram.

So We have presented to view of Imam Ahmad as mentioned by one of His Trustworthy and Great Companion, along with explanation of the words by Scholars of AhluSunnah, that Imam Ahmad considered it Makrooh, and not Haram.

If someone claims that Imam Ahmad said otherwise, He should give the chain to Him.

This article is deduced from work of brother Nasir Hussein.