Question
Is keeping a fist-length beard obligatory?
Answer
Lengthening the beard is an emphasised Sunnah of all the Prophets. The Hanafi/Deobandi position is that it is obligatory to keep the beard at least a fist-length; shaving it or trimming it below a fist-length is impermissible.
وَاللّٰهُ أَعْلَمُ