it has to do with speaking
Psa 139:19 Oh that you would slay the wicked, O God! O men of blood, depart from me!
Psa 139:20 They speak against you with malicious intent; your enemies take your name in vain!
lift from hebrew "take up"
See how this is used
Num 23:7 And Balaam
took up his discourse and said, "From Aram Balak has brought me, the king of Moab from the eastern mountains: 'Come, curse Jacob for me, and come, denounce Israel!'
Isa 14:4 you will take up this taunt against the king of Babylon: "How the oppressor has ceased, the insolent fury ceased!
Job 27:1 And Job again took up his discourse, and said:
Job 27:2 "As God lives, who has taken away my right, and the Almighty, who has made my soul bitter,
Psa 81:1 To the choirmaster: according to The Gittith. Of Asaph. Sing aloud to God our strength; shout for joy to the God of Jacob!
Psa 81:2 Raise a song; sound the tambourine, the sweet lyre with the harp.
Keil and Delitzsch
The word prohibits all employment of the name of God for vain and unworthy objects, and includes not only false swearing, which is condemned in
Lev_19:12 as a profanation of the name of Jehovah, but trivial swearing in the ordinary intercourse of life, and every use of the name of God in the service of untruth and lying, for imprecation, witchcraft, or conjuring; whereas the true employment of the name of God is confined to “invocation, prayer, praise, and thanksgiving,” which proceeds from a pure, believing heart. The natural heart is very liable to transgress this command, and therefore it is solemnly enforced by the threat, “for Jehovah will not hold him guiltless” (leave him unpunished), etc
Lev 19:12 You shall not swear by my name falsely, and so profane the name of your God: I am the LORD.
Lev 24:15 And speak to the people of Israel, saying, Whoever curses his God shall bear his sin.
Lev 24:16 Whoever blasphemes the name of the LORD shall surely be put to death. All the congregation shall stone him. The sojourner as well as the native, when he blasphemes the Name, shall be put to death.
blasphemy
A primitive root; to puncture, literally (to perforate, with more or less violence) or figuratively (to specify, designate, libel): - appoint, blaspheme, bore, curse, express, with holes, name, pierce, strike through.
Swear
1) to swear, adjure
1a) (Qal) sworn (participle)
1b) (Niphal)
1b1) to swear, take an oath
1b2) to swear (of Jehovah by Himself)
1b3) to curse
1c) (Hiphil)
1c1) to cause to take an oath
1c2) to adjure
when this is really bad is when we swear or call God as witness and are lying or being trivial (joking)
ISBE
David's sin is an occasion to the enemies of the Lord to blaspheme
2Sa 12:13 And David said to Nathan, I have sinned against Jehovah. And Nathan said to David, Jehovah also has put away your sin; you shall not die.
2Sa 12:14 Only, because by this deed you have given great occasion to the enemies of Jehovah to blaspheme, this child born to you shall surely die.
Blasphemy in other places
A primitive root; to scorn; or (
Ecc_12:5) by interchange for H5132, to bloom: - abhor, (give occasion to) blaspheme, contemn, despise, flourish, X great, provoke.
Psa 74:18 Remember how the enemy hurls insults, O Lord, and how a foolish nation blasphemes your name!
The NET has
Lev 24:16 and
one who misuses the name of the Lord must surely be put to death. The whole congregation must surely stone him, whether he is a foreigner or a native citizen; when he misuses the Name he must be put to death.
Remember we are commanded to "Hallow" his name.
We are to call on His name and Bless it.