Try To Find Hidden Catches

I searched the inside of the coffin for hidden catches that I could activate to open it and escape, but there didn't seem to be any. My probing fingers did however encounter several other things that might be of use. First was a dagger, in a simple leather sheath. Next was a large pouch containing a number of small items that I couldn't identify without opening it. Third was a suit of heavily embroidered garments, made from silk, which seemed like they were tailored for me. Lastly, I found a book of some ilk sewn into the pillow under my head.

The problem remained, how did I escape this coffin?

A: Means Of Escape...
A1: Try to shove the lid off... (Strength.)
A2: Try to pry the seams open with the dagger. (Dexterity.)
A3: See if there is a "bell of the living"... (Wisdom.)
A4: Slam my body side to side to try to break open the casket. (Constitution.)