YOU SAID:

So he vowed to be his husband at the altar

INTO JAPANESE

それで彼は祭壇で夫になることを誓いました

BACK INTO ENGLISH

So he vowed to be a husband on the altar

INTO JAPANESE

それで彼は祭壇の上で夫になることを誓いました

BACK INTO ENGLISH

So he vowed to be a husband on the altar