Rumi's Masnavi - The clear mirror of bread is truly the hungry man; tinder, likewise, is the mirror of that (the stick or flint) from which fire is struck.

The clear mirror of bread is truly the hungry man; tinder, likewise, is the mirror of that (the stick or flint) from which fire is struck.

آینه‌‌ی صافی نان خود گرسنه ست ** سوخته هم آینه‌‌ی آتش زنه ست‌‌

Not-being and defect, wherever they arise (appear), are the mirror which displays the excellence of all crafts.

نیستی و نقص هر جایی که خاست ** آینه‌‌ی خوبی جمله‌‌ی پیشه‌‌هاست‌‌

When a garment is neat and well-stitched, how should it enable the tailor to exhibit his skill? 3205

چون که جامه چست و دوزیده بود ** مظهر فرهنگ درزی چون شود

Trunks of trees must be unhewn in order that the woodcutter may fashion the stem or the branches (and thus exercise his craft).

ناتراشیده همی‌‌باید جذوع ** تا دروگر اصل سازد یا فروع‌‌

The doctor who sets broken bones goes to the place where the person with the fractured leg is.

خواجه‌‌ی اشکسته بند آن جا رود ** که در آن جا پای اشکسته بود

How shall the excellence of the art of medicine be made manifest when there is no emaciated invalid?

کی شود چون نیست رنجور نزار ** آن جمال صنعت طب آشکار

How shall the (power of the) Elixir be shown if the vileness and baseness of coppers is not notorious?

خواری و دونی مسها بر ملا ** گر نباشد کی نماید کیمیا

Defects are the mirror of the quality of perfection, and that vileness is the mirror of power and glory, 3210

نقصها آیینه‌‌ی وصف کمال ** و آن حقارت آینه‌‌ی عز و جلال‌‌

Because (every) contrary is certainly made evident by its contrary; because honey is perceived (to be sweet by contrast) with vinegar.

ز آن که ضد را ضد کند پیدا یقین ** ز آن که با سرکه پدید است انگبین‌‌

Whoever has seen and recognised his own deficiency has galloped with ten horses (made rapid progress) in perfecting himself.

هر که نقص خویش را دید و شناخت ** اندر استکمال خود ده اسبه تاخت‌‌