how is it so sweet! —

 being an enjoyable abode —

 one who is enjoyable as we experience him repeatedly —

being perfectly enjoyable for those who are fully engaged (in this beauty) —

with pleasing enjoyable aspects —

like a nectar to the ears —

very sweet —

 being good —

pleasing prosperity [of ṣrīvaishṇavas and their activities] —

those who are being friendly to them —

now, ī know (you) firmly —