Learn Icelandic: Sambandið mun sameina okkur um alla eilífð, hvort sem við lifum eða deyjum. - The bond will unite us for all eternity, whether we live or die.

Hvort sem translates to "whether" and pairs with eða ("or") to form a concessive disjunction. This means it sets up two contrasting scenarios (við lifum eða deyjum) to show that the main action (Sambandið mun sameina okkur) will happen regardless of which option comes true.

Do verbs following hvort sem take the indicative or subjunctive mood?

In modern Icelandic, hvort sem usually takes the indicative mood when presenting realistic or factual alternatives, which is why we see the indicative forms lifum and deyjum here. You would generally only use the subjunctive if the scenarios were highly hypothetical.

Why does the phrase um alla eilífð use the accusative case?

The preposition um governs the accusative case when it is used to express time or duration. Because eilífð (eternity) is a feminine noun, the adjective allur must also take its feminine accusative form, which is alla.

Besides an emotional "bond," what else can sambandið refer to?

The root word samband broadly means "connection" or "relationship." While it perfectly describes a romantic or spiritual bond here, it is also the standard word for practical connections, such as an internet connection (netsamband) or being in touch with someone (vera í sambandi).