Here in this story, Abdullah ibn Mas'ood, the one very knowledgeable amongst the Sahabah in the Shariah are telling us Shariah principles: 1. That in matters pertaining to Ibadat (worship), all matters are Haram (unlawful), not allowed, EXCEPT if there is a proof from the Qur'an and Sunnah.
[1] Heto ang kompletong Isnaad: Sinabi ni Al-Bukhari na sinabi sa amin ni Muhammad ibn Salaam, na sinabi ni Abu Mu’aawiyah, na sinabi ni A’maash, na sinabi ni ’Umar bin Murrah, mula kay Sa’eed bin Jubair, mula kay Ibn ’Abbas.