Is it true that there is a disagreement among scholars regarding the required length of the beard, and is a length of one finger-joint or slightly more sufficient, and what are the sayings of the scholars of the four schools of thought and their evidence regarding the obligatory length of letting the beard grow?

We have not found in the statements of scholars an estimation of the beard's length by an anmula (fingertip) or similar measures. Some scholars have prohibited taking anything from the beard, while others permitted it if it exceeded a fistful, or became unusual, or disfigured. Some have held that taking from it is a Sunnah, and some that it is obligatory if it exceeds a fistful. Others have said that it is permissible to take from it if it becomes very long, to the extent of being unusual, or if it is for the purpose of maintaining a suitable appearance. It has been narrated from the Companions that they would take what exceeded a fistful. Some interpreted "I'faa'" (letting the beard grow) as not taking anything from the beard at all, while others interpreted it as not resembling non-Arabs by shaving it. It is permissible to take from it when necessary to tidy it.