Rubies in the Soldiers' Laps

From D5.29, Iskandar Seeks the Fount of Life. It illustrates D5.29.87–91:

D5.29.87
They left the Water’s region for the plain,And from the dark emerged with all their train.
D5.29.88
They searched their sleeves and folds of clothing through;Their faults and shortages came into view.
D5.29.89
One lap was full of rubies, bright and fair;Another held uncut gems, just as rare.
D5.29.90
Who took but little now was sorrow-torn:He left green gems as though each were a thorn.
D5.29.91
Still more regretful was the man whose handHad left those precious jewels upon the land.