Quatrain 15

ای پیر خردمند پگه‌تر برخیز
وان کودک خاک‌بیز را بنگر تیز
پندش ده و گو که نرم نرمک می‌بیز
مغز سرکیقباد و چشم پرویز

Dashti, quatrain 38, p. 251

ey pir-e kheradmand pagahtar barkhiz
vaan kudak-e khaakbiz raa bengar tiz
pandash deh o gu ke narm narmak biz
maghz-e sar-e keyqobaad o cheshm-e parviz

O wise old man, rise up earlier in the morning and carefully watch that child who sifts the dust.  Counsel him and say: 'Gently, gently sift the brain of Kai-qūbad's head and the eyes of Parvīz!'
Forughi, quatrain 112, translated by Parichehr Kasra in her edition

O Wise Graybeard! Awake to morning breeze;
Behold the boy who sweeps the dust, and please,
Counsel him thus: "O gentle, gentle be
With head of Qobad and eyes of Parveez."

Saidi, quatrain 87

See Saidi's notes, p. 248-249 on the ancient hero Key-Qobad, founder of the Keyanian dynasty, and Khosrow Parviz (Khosrow the Conqueror) or Khosrow II, Sasanian dynast who ruled from 590-628, C.E. On the Keyanian dynasty and Key-Qobad and also for Khosrow Parviz  see the online Encyclopaedia Iranica  articles highlighted. 

Translation & Discussion of the quatrain: 1. O wise old man, get up early in the dawn (see on pagahtar below). 2. The boy who sweeps the ground/the boy, the groundsweeper/the groundsweeping boy, keep a sharp eye on him - khaakbiz can be a compound noun, like the English "streetsweeper" or maybe it should be regarded as a compound adjective (biz is the present stem of the verb bikhtan appended to khaak).  As often noted on this site, these compounds are frequent and add richness and color to the language.  Following Sanskrit classification, this is a tat purusha compound, where the first element has an object relationship to the second, here "sweeper of the ground" similar to English "streetsweeper".  3. Advise him and say/by saying "gently, gently sweep ... the quote is direct and introduced by ke. gu ke may be translated  "by saying"The imperative mibiz -- this form usually takes no prefix or it will have be prefixed, but sometimes mi as here (for the sake of meter?).  4. the brain of Keyqobad and the eye(s) of Parviz" -- maghz-e sar "the marrow of the head", English "marrow" and Persian maghz have a common ancestor in the Indo-Iranian noun-stem *mozgho-. The speaker of the quatrain lets us know that these heroes, the one legendary and the second, Khosrow II, historical, once powerful monarchs, are now reduced to death and dust (see also quatrains 24 & 55).

A note on پگه‌تر , pagahtar, pagah, "dawn", "early morning" + tar, the comparative suffix. I was curious about the prefix pa and also the suffix  -tar, the latter a strange use of the comparative to my thinking.  I did some research and found that pa comes from Avestan and old Iranian upâ, cognate with Greek hypo and Latin sub.  Prefixed to gah (گاه/گه), it carries the meaning of "toward/about/at/at the time of" so pagah means in time/at an early time/betimes".  By "in time" it will also convey the sense of "soon" or "quick" as in sobh-e zud, "early in the morning". But what is the significance of tar? To get up earlier? Earlier than the boy who sweeps?

I then decided to look through Oswald Szemerényi's Introduction to Indo-European Linguistics (the translation from the original German) to see if anything would turn up. Szemerényi writes (page 199) that new Persian astar, "mule" is derived from the Old Indic ašva-tara (ashva is the Sanskrit for horse). To the point, the suffix tara was not intended to have a comparative use as "nearly horse" but had a "differentiating value"  or "separative function".  It differentiated the mule "of the horse kind" from the ass.  So I believe that pagahtar reflects this distinction by differentiating early from late dawn. So it does not mean "earlier"  but "the early time in the dawn and not later".  No time to be lost for the wise old man!