Albert Barnes Commentary Exodus 5:12

"So the people were scattered abroad throughout all the land of Egypt to gather stubble for straw." — Exodus 5:12 (ASV)

Stubble instead of straw - Rather, for the straw: that is, to be prepared as straw. This marks the season of the year, namely, early spring, after the barley or wheat harvest, toward the end of April. Their suffering must have been severe: at that season the pestilential sand-wind blows over Egypt some 50 days, hence, its name - Chamsin. (compare Genesis 41:6 note).