John Gill Commentary Ecclesiastes 10:9

"Whoso heweth out stones shall be hurt therewith; [and] he that cleaveth wood is endangered thereby." — Ecclesiastes 10:9 (ASV)

Whoso removes stones shall be hurt by it
That carries them from the quarry, where they are dug; or takes them from a heap, where they lie; or that attempts to pull them out of a building, where they are put; or removes them from places, where they are set as boundaries and landmarks; all which is troublesome, and by which men get hurt; the stones fall upon them, or are too heavy for them, or they do what they should not do, and so bring themselves into trouble; as do all such persons who are for removing the boundaries of commonwealths and communities, and for changing laws, and altering constitutions;

[and] he that cleaves wood shall be endangered by it ;
of cutting himself: so he that sows discord among brethren, that makes divisions in families, neighbourhoods, kingdoms, and churches; see (Proverbs 6:16Proverbs 6:19) (Romans 16:18) .

Jarchi renders it, "shall be warmed" or "heated", according to the sense of the word, as he thinks, in (1 Kings 1:2) ; though he understands it of being profited by studying in the law and the commandments; of which he interprets the clause; and Ben Melech observes, that the word so signifies in the Arabic language; and Mr. Broughton renders it, "shall be heated by it". The Targum paraphrases it,

``shall be burnt with fire, by the hand of the Angel of the Lord:'' or, however, he may be overheated and do himself hurt, as men, that kindle the flame of contention and strife, often do.