By the time of the Hebrew Book of Ezra (550 to 450 BCE), receiving salt from a person was synonymous with drawing sustenance, taking pay, or being in that person's service. At that time, salt production was strictly controlled by the monarchy or ruling elite. Depending on the translation of Ezra 4:14, the servants of King Artaxerxes I of Persia explain their loyalty variously as "because we are salted with the salt of the palace" or "because we have maintenance from the king" or "because we are responsible to the king".[1]
Salarium
Similarly, the Latin word salarium linked employment, salt, and soldiers, but the exact link is not very clear. More modern sources maintain instead that although Roman soldiers were typically paid in coin, the word salarium is derived from the word sal (salt) because at some point a soldier's salary may have been an allowance for the purchase of salt[4] or the price of having soldiers conquer salt supplies and guard the Salt Roads (Via Salaria) that led to Rome.[5][6] However, there is no ancient evidence for either of these hypotheses.[7]
Some people even claim that the word soldier itself comes from the Latin sal dare (to give salt),[citation needed] but mainstream sources disagree,[8][9] noting that the word soldier more likely derives from the gold solidus,[10] with which soldiers were known to have been paid[citation needed].
I thought they were paid partly in salt? (How we got the word "salary," they say.)
Average pay for Roman Legionnaire
https://ancientfinances.com/2018/02/13/average-pay-for-roman-legionnaire/
https://wikiless.org/wiki/Salary?lang=en#First_paid_salary
Salarium