Jesus uses a question to teach the crowd. AT: "it cannot be made salty again." or "no one can make it salty again." (See: [[rc://en/ta/man/translate/figs-rquestion]] and [[rc://en/ta/man/translate/figs-activepassive]])
People use manure to fertilize gardens and fields. Salt without taste is so useless it is not even worth mixing with manure. AT: "compost heap" or "fertilizer"
It may be more natural in some languages to use the second person: "You who have ears to hear, hear" (See: [[rc://en/ta/man/translate/figs-123person]])
Possible meanings are 1) "Everyone" since everyone has ears or 2) "Whoever has the ability to understand" which refers to those who are willing to listen to God. (See: [[rc://en/ta/man/translate/figs-idiom]])
# let him hear
"he should listen well" or "he should pay attention to what I say"