Swear by His Name, what the real meaning of this command?

Question

Could someone explain to me the meaning of the phrase: וּבִשְׁמוֹ, תִּשָּׁבֵעַ in Devarim 6:13? It seems to be the positive command of the prohebition mentioned in Vayikra 19:12...

I know that the Tur HaAroch explains it as "and (only) in His name are you to render an oath"; this doesn't mean that it is a commandment to swear oaths, but if the occasion arises when you cannot avoid having to swear an oath, the only truth you must swear by is the truth known as Hashem. Likewise IBN Ezra (and many others) explain it as "to swear by His name and not in the name of any other gods" (compare, “every tongue shall swear” [Isaiah 45: 23]). In other words, you shall not swear in the name of any god, other than G-d alone. But you may swear to affirm testimony, or to confirm a contract — so long as it is true. Do not follow other gods since you may not swear in their name.

But how should I understand this command as it seems to imply that one has to do something. What's the true meaning behind it? Could it be rendered or understood as a command to act upon His Name, call upon His Name (see Tehillim 105:1; call upon His name, make known His doings among the peoples)?

Answer 1

The Rambam, Sefer HaMitzvos Aseh #7 understands it as a command to swear in Hashem's name when it is necessary to swear in someone/something's name. This is to preclude other deities. This is like what you brought from the Ibn Ezra and Tur.

However, the Ramban ad. loc. disagrees, and says the Torah is simply giving permission to swear in Hashem's name. He sees no command to do so, so it shouldn't be counted as a mitzvah. Rambam also doesn't say it's an obligation, simply you fulfill a mitzvah when you follow the Torah's instructions. Similar to ritual slaughter, or using a mikvah. One doesn't have to slaughter or go to a mikvah, but should if they want kosher meat or to become pure.

Note that neither see the verse as prescribing an obligation to swear.

The Sefer HaChinuch #435 brings their dispute. The Semag Aseh #123 and Semak #108 go with the Rambam.