Albert Barnes Commentary Luke 1:29

"But she was greatly troubled at the saying, and cast in her mind what manner of salutation this might be." — Luke 1:29 (ASV)

Troubled at his saying. Disturbed or perplexed at what he said. It was so unexpected, so sudden, so extraordinary, and was so high an honor, that she was filled with anxious thoughts, and did not know what to make of it.

Cast in her mind. Thought, or revolved in her mind.

What manner of salutation. What this salutation could mean.