"The Prophet (ﷺ) prohibited studding the stallion."

There are narrations on this topic from Abu Hurairah, Anas, and Abu Sa'eed.

The Hadith is Ibn 'Umar is a Hasan Sahih Hadith. This is acted upon according to some of the people of knowledge. There are those who made concession for accepting an honorarium for that.
Jami` at-Tirmidhi Book 14, Hadith 75
← Previous Hadith That the Prophet (ﷺ) said: "Do not withhold surplus water so that it is prevented from the pasture."

This Hadith is Hasan Sahih.

Abu Al-Munhal's name is 'Abdur-Rahman bin Mut'im, he is from Al-Kufah, and he is oen that Habib bin Abi Thabit reports from. Abu Al-Munhal Sayyar bin Salamah is from Al-Basrah, he is the companion of Abu Barzah Al-Aslami.

Jami` at-Tirmidhi Book 14, Hadith 74 Next Hadith → "A man from (the tribe of) Kilab asked the Messenger of Allah (ﷺ) about studding a stallion and he prohibited it. So he said: 'O Messenger of Allah! We stud the stallions so that we get honorarium (from the owners of the female horse)!' So he permitted it for honorarium."

This Hadith is Hasan Gharib, we do not know of it except as a narration of Ibrahim bin Humaid, from Hisham bin 'Urwah.

Jami` at-Tirmidhi Book 14, Hadith 76