Right
若 supplies the sound — ruò drifting to nuò through the regular r/n alternation seen across the
若 phonetic group (
诺 promise,
偌 such).
若 originally depicted a kneeling figure with hands raised, combing the hair, the seed for 'agreeable, compliant.' For
喏 the agreement flavour fits the 'yes, all right' interjection sense.