פירוש על שמות 5:7

תבן STRAW — In old French estouble; English stubble. They used to knead this into the clay.

לתת תבן, the straw was mixed in with the mud to make the mud bricks firmer and less likely to crumble.

לא תאספון לתת תבן, “do not continue to supply straw, etc.” It is entirely possible that this decree was in force for only a single day and that the unusual letter א in the word תאספון is proof of this. This is the view of Rabbeinu Chananel.