Happy almost Birthday to my grandma!
This comic is also spawned by a sermon, one that talked about marriage. Back in the like 90's, SWAK meant to "Seal With A Kiss" and it was used on envelopes to mean you were sending your love, at least that's what I recall about it. I had some stickers and I remember one of them was SWAK. I really liked stickers and would put them all over my pen pal letters. Wow, the 90's were a while ago. Hand-made letters are still a nice thing to do, but I stick with making cards for people which are a type of letter so that still counts I think.
Explanation: Usually, the minister ends the marriage ceremony by saying "By the power vested in me, you may kiss your bride" or something along those lines. SWAK means to seal with a kiss, usually meaning seal an envelope, but in this case it would be sealing a covenant and I think the slang works. It would just be super informal at an official ceremony. But many weddings are not super formal. So use at your discretion. Wow, I super misspelled that last word but spell checker had my back.
Extra note: Back in my college days, a pastor mentioned how after he was ordained, a friend asked him to officiate a marriage. Unsure if he could, he called up his dad who was also a minister and asked "Do I have THE POWER?" Upon further inquiry ("son, what in the world are you talking about?"), he specified if he had the power to say "by the power vested in me", and his dad told him that since he was ordained then he did indeed have THE POWER.
Text:
Minister: By the power vested in me, please SWAK this covenant!
Bride and Groom: *standing there, maybe awkwardly*