commit (something) to memory
To make an effort to learn something; to memorize something. Everyone in our English class had to commit a poem to memory and then recite it before the class. I just can't seem to commit your phone number to memory!
commit something to memory
to memorize something. Do we have to commit this poem to memory? The dress rehearsal of the play is tomorrow night. Please make sure you have committed all your lines to memory by that time.
commit to memory
Learn by heart, memorize, as in The director insisted that the altos commit their part to memory by Tuesday. First recorded in 1875, this phrase today is often replaced by the shorter memorize.