Here "bear the yoke" represents suffering. The abstract noun "his youth" can be expressed with the word "young." AT: "that he suffer while he is young" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-abstractnouns]])
The phrase "in silence" refers to not speaking. Here it may refer specifically to not complaining. AT: "Let him sit alone without speaking" or "Let him sit alone and not complain"
# when it is laid upon him
"when the yoke is laid upon him." Here the yoke represents suffering. AT: "when he suffers" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Putting the mouth in the dust represents bowing down with one's face on the ground. AT: "Let him lie down with his mouth on the ground" (See: [[rc://en/ta/man/translate/figs-metonymy]])