Here "word" is a metonym for "a message." This means that he sent a messenger. AT: "I sent a messenger" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# to the king to say
The message here for the king is written as if Absalom were the speaker. Absalom was asking Joab to speak the message on his behalf. The full meaning of this statement can be made clear. AT: "to say to the king on my behalf" or "to ask the king for me" (See: [[rc://en/ta/man/translate/figs-explicit]])
# the king's face
Here "king's face" refers to the king himself. AT: "the king" (See: [[rc://en/ta/man/translate/figs-synecdoche]])