Is mind the most valuable thing according to the Lord Buddha? Is mind the most valuable thing according to the buddha that we should protect by doing anything to everything?

Are there any metaphors said by Lord Buddha on the value of protecting the mind vs doing other things ?
In MN 56, we see disciples of the founder of Jainism, Mahavira (called Nigantha Nataputta in the suttas) debate with the Buddha.

Apparently, Nigantha Nataputta taught that physical deeds weigh more heavily than mental deeds.


  “Reverend Gotama, Nigaṇṭha Nātaputta doesn’t usually speak in terms of
  ‘deeds’. He usually speaks in terms of ‘rods’.”
  
  “Then how many kinds of rod does Nigaṇṭha Nātaputta describe for
  performing bad deeds?”
  
  “Nigaṇṭha Nātaputta describes three kinds of rod for performing bad
  deeds: the physical rod, the verbal rod, and the mental rod.” .....
  
  “Of the three rods thus analyzed and differentiated, which rod does
  Nigaṇṭha Nātaputta describe as being the most blameworthy for
  performing bad deeds: the physical rod, the verbal rod, or the mental
  rod?”
  
  “Nigaṇṭha Nātaputta describes the physical rod as being the most
  blameworthy for performing bad deeds, not so much the verbal rod or
  the mental rod.”


What did the Buddha teach?


  “Tapassī, the Realized One doesn’t usually speak in terms of ‘rods’.
  He usually speaks in terms of ‘deeds’.”
  
  “Then how many kinds of deed do you describe for performing bad
  deeds?”
  
  “I describe three kinds of deed for performing bad deeds: physical
  deeds, verbal deeds, and mental deeds.” .....
  
  “Of the three deeds thus analyzed and differentiated, which deed do
  you describe as being the most blameworthy for performing bad deeds:
  physical deeds, verbal deeds, or mental deeds?”
  
  “I describe mental deeds as being the most blameworthy for performing
  bad deeds, not so much physical deeds or verbal deeds.”


And later the Jain householder Upali came to debate with the Buddha.


  When he said this, the householder Upāli said to him, “Good, sir, well
  done by Tapassī! The honorable Tapassī has answered the ascetic Gotama
  like an educated disciple who rightly understands their teacher’s
  instructions. For how impressive is the measly mental rod when
  compared with the substantial physical rod? Rather, the physical rod
  is the most blameworthy for performing bad deeds, not so much the
  verbal rod or the mental rod.”  .....
  
  “What do you think, householder? Take a Jain ascetic who is restrained
  in the fourfold restraint: obstructed by all water, devoted to all
  water, shaking off all water, pervaded by all water. When going out
  and coming back they accidentally injure many little creatures. Now,
  what result does Nigaṇṭha Nātaputta say they would incur?”
  
  “Sir, Nigaṇṭha Nātaputta says that unintentional acts are not very
  blameworthy.”
  
  “But if they are intentional?”
  
  “Then they are very blameworthy.”
  
  “But where does Nigaṇṭha Nātaputta say that intention is classified?”
  
  “In the mental rod, sir.”
  
  “Think about it, householder! You should think before answering. What
  you said before and what you said after don’t match up. But you said
  that you would debate on the basis of truth.”  ......
  
  “Sir, I was already delighted and satisfied by the Buddha’s very first
  simile. Nevertheless, I wanted to hear the Buddha’s various solutions
  to the problem, so I thought I’d oppose you in this way.
  
  Excellent, sir! Excellent! As if he were righting the overturned, or
  revealing the hidden, or pointing out the path to the lost, or
  lighting a lamp in the dark so people with good eyes can see what’s
  there, the Buddha has made the teaching clear in many ways. I go for
  refuge to the Buddha, to the teaching, and to the mendicant Saṅgha.
  From this day forth, may the Buddha remember me as a lay follower who
  has gone for refuge for life.”


And using this simile and other similes, the Buddha convinced Upali that mental deeds weigh more heavily than physical deeds and verbal deeds. Thereafter, Upali became a Buddhist.