Sostenerme comes from the verb sostener, meaning 'to sustain', 'to hold up', or 'to support'. It's a beautiful and slightly less common verb in everyday song lyrics, making it stand out.
In the context of "REGALO DE DIOS," the singer uses it to express deep gratitude and reliance on their loved one, singing "Y me diste tus manos para sostenerme" (And you gave me your hands to hold me up/sustain me). It conveys a sense of emotional and perhaps even physical support, highlighting the profound impact this person has had on their life.
Gabito Ballesteros and Carín León call this person a gift from God, literally: "Regalo de Dios, Dios" [Gift from God, God]. The song plays like a retelling of a first date. It started at a coffee shop and ended at a club, dancing close to Adele: "Música de Adele, bien juntitos bailamos" [Adele music, we danced real close], with a single slow kiss and a whispered "Vamos lento" [Let's go slow].
Then it gets a little dramatic about it, in a fun way. Even if NASA says the world's about to end, none of that matters as long as they're together: "Mientras esté yo, nada te va a pasar" [As long as I'm here, nothing's gonna happen to you]. Gabito even drops his own name mid-song, "Soy Gabito, viejo" [I'm Gabito, man], before the bridge turns almost philosophical: "El sol morirá" [The sun will die], and a piano key might stop sounding, but what's inside keeps going. It all lands on one line that sums up the whole thing: "Somos uno más uno, la perfecta ecuación" [We're one plus one, the perfect equation].