A guard is read as protection and as limits — something defended, or something keeping you out. Dream books ask which side of the gate you were standing on.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.