Pirkei Avot - Ethics of the Fathers

~Level 1~
Bartenura - "whoever honors the torah.." - one who expounds (doresh) the extra letters or missing letters of the words in the torah and derives the reasons for every tiny detail and thus demonstrates that there is nothing superfluous in it - there is no greater honor of torah than this.
Alternatively, it refers to one who honors a sefer torah (torah scroll) and honors those who study torah. All these things are included in honoring the torah.

~Level 2~
Rabeinu Yonah - "one who honors the torah" - what is honoring the torah? To not leave (torah) books on the floor. To not sit on a bench or chair where books lie. To have reverence for words of torah and honor it and those who study it.

It is known from many verses and also from reason that whoever speaks good on the good [people] and on the torah sages - we can assume he is a tzadik (righteous person). And whoever judges them negatively and argues on their deeds saying they are wrong and he does not see any merit in them but when one speaks about the wicked, he justifies their deeds - it is clear this person has wickedness within him. Do not have any doubt about it.

With this you can test the hearts of people.. For even though one cannot know if his fellow is a heretic. For it is hidden in their heart and they pretend verbally to believe.

"is himself honored before others" - G-d causes others to honor him since he honors the torah as before.