[mitch5501]

On rereading an ealier post I note I didn't explain what I meant by quoting Hebrews 5:14 and Matthew 5:13

It was in relation to the 'restrainer'.

Assuming "strong meat" is deep Spiritual truth and salt is a restrainer of decay when used on meat,it makes me think the body of believers is the retrainer.

grace and peace to you both

[Yosemitest]

"Assuming "strong meat" is deep Spiritual truth ... "

That's a safe assumption.
Remember:

" ... seeing ye are dull of hearing.
For when for the time YE OUGHT TO BE teachers,
YE HAVE NEED THAT ONE TEACH YOU AGAIN
which be the first principles of the oracles of God;
and ARE BECOME SUCH AS HAVE NEED OF MILK,
AND NOT STRONG MEAT.
For EVERY ONE THAT USETH MILK IS UNSKILFUL IN THE WORD OF RIGHTEOUSNESS:
for he is a babe.
But STRONG MEAT BELONGETH TO THEM THAT ARE OF FULL AGE,
even those who
by reason of use
have their senses exercised TO DISCERN
BOTH GOOD AND EVIL. "

As far as "salt", read what the Matthew Henry's Commentary » Matthew » Chapter 5 » Verses 13–16 has to say about it.