Assalaamu alaikum brother Ibrahim!
Our first taker for the riddle :-)
Well let's see how you did...
I would suggest that he eat the Dates on the calendar,
Correct! As we know dates are nutritious

drink from the springs in the matress,
Pretty fancy

2/3 answered.
What about the last part...?
and as he has made a hole in the matress, he could crawl through the hole and escape?
Not quite - but on the right track. It's a *little* more complicated than that!!