A text of Hadith is rejected if it is against natural phenomenon. This means that if the content of the Hadith goes against what is known through reason, observation, or scientific evidence, it is considered invalid. This is because Islam encourages the pursuit of knowledge and the use of reason, and anything that contradicts natural phenomena or established knowledge is deemed unreliable. Therefore, Hadith scholars have to critically examine and authenticate the Hadith based on their chains of transmission and their content to ensure their accuracy and conformity with the principles of Islam.