Outward silence means no words are audibly uttered, even though an intelligible meaning may be present. Inward silence considers the absence of meaningful inner speech. Without distinguishing the range of these senses, one cannot infer the absence of an inner meaning from an absence of sound.
A student may mentally prepare an answer without yet saying anything. Outward silence coexists with an intended content.
The human example distinguishes different senses of speech and silence; it does not impose the temporal beginning or ending of human thought on divine speech.