All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
We have clarified in previous Fataawa that boxing in its known form is forbidden because it involves causing harm to others and striking the face. The book Al-Fiqh Al-Islaami wa-Adillatuh reads: "Freestyle wrestling, boxing, and similar sports are impermissible because of the physical harm they cause to human or animal life. Islam forbids such perverted sports because they involve flagrant violation of the Prophet’s statement: 'When anyone of you fights, let him avoid (striking) the face.' [Al-Bukhaari on the authority of Abu Hurayrah] If there is no harm incurred on either side in wrestling nor striking of the face, then it is permissible to practice it. It is also deemed permissible if it involves training for strength, combat, and self-defense. The Prophet wrestled with Rukaanah and defeated him." [End of Quote]
Watching such forbidden matches, even if the ‘Awrah of the contenders is properly covered, implies tacit approval and consent of their actions. Muslim jurists stated that it is forbidden to watch what is forbidden to do. It is stated in Haashiyat Al-‘Adawi ‘ala Kifaayat At-Taalib Ar-Rabbaani regarding the ruling on images: "In summary, what is forbidden to do is forbidden to look at, what is disliked to do is disliked to look at, and what is allowable to do is allowable to look at." [End of Quote]
It is also stated in the Shaafi‘i book Haashiyat Ar-Ramli about the prohibition of provoking animals against one another (to instigate a fight): "It is forbidden to watch these prohibited activities, because watching constitutes helping them (the doers) in carrying out what is forbidden. It is said in Tuhfat Al-Muhtaaj by Al-Haytami: 'All that is prohibited is forbidden to watch.'" [End of Quote]
The Shaafi‘i book of Fiqh Nihaayat Az-Zayn fi Irshaad Al-Mubtadi’een, in the chapter on the clothes and jewelry that are prohibited for use, reads: "What is forbidden in and of itself is forbidden to watch." [End of Quote]
Allah Knows best.