The Prophet (ﷺ) was asked, 'What type of earning is best?' He replied, "A man's work with his hand and every transaction which is free from cheating or deception." [Reported by al-Bazzar; al-Hakim graded it Sahih (authentic)].
A bare bones reference to proof of work (“with his hand”), from our Prophet(S.A.W.), 1400 years ago.
This is a baseline for the bitcoin ethos