The poet talks about the ‘sadness’ which is related to the human’s ceaseless activity and moving towards his own ruin on account of his unanalyzed actions. He regrets the rush of outdoing others that has made one forget the values of humanity.

No, he doesn't. He makes it very clear that 'stillness' should not be confused an equated to 'total inactivity'. Total inactivity brings death. But Neruda has 'no truck with death'. His stillness means cessation of hostile and harmful human activities.

Keeping quiet does not signify that we should stop doing everything. It simply means that we must stop doing all those things that are lethal to our mother earth. Mother Earth stays quiet nurturing life on it. Similarly, we should also make attempts to do things that support nature to maintain life on it.

Instructing the people to stay quiet for a moment, Pablo Neruda hints at a state of equilibrium where without any movement or activity we shall get a chance to introspect within ourselves about our views, and activities whether we are right or wrong, true or false. The poet here hints at to introspect to work for unity, peace, and universal brother hood. He advises us to have the retrospection (to look back at our past events) so that we can evaluate our actions in future.

(i) The poet wants us to keep quiet and give up endless activity to be able to introspect. He wants us to break free of the barriers of language and be united in a moment of eloquent silence.

(ii) The poet wants us to give up our endless, incessant activities and be lost in eloquent, calm and peaceful silence break free of all barriers of language and communication.

(iii) When the poet says ‘ not move our arms’, he wishes to convey that in the moment of eloquent peaceful silence we must all give up whatever we are doing. He means to say there must be absolutely no action, no activity and no communication or interaction whatsoever.