Albert Barnes Commentary Luke 17:37

"And they answering say unto him, Where, Lord? And he said unto them, Where the body [is], thither will the eagles also be gathered together." — Luke 17:37 (ASV)

See Barnes on Matthew 24:26.

Where, Lord? Where, or in what direction, will these calamities come? The answer implies that it would be where there is the most guilt and wickedness. Eagles flock where there is prey. So, He said, these armies will flock to the place where there is the most wickedness; and by this, their thoughts were immediately directed to Jerusalem, the place of prominent wickedness, and the place, therefore, where these calamities might be expected to begin.