745.
In general 'bird' means thoughts. This is clear from what has been stated in several places already about birds meaning intellectual concepts or rational concepts. In those places however they are called
'birds of the air'a whereas here it is simply 'bird', which is why thoughts in general are meant. Indeed there are many kinds of birds, clean and unclean, which in verse 14 below are differentiated
as birds, flying creatures, and winged creatures. Clean ones are thoughts about truth, the unclean are false thoughts, which will in the Lord's Divine mercy be dealt with later on.
Notes
a lit. birds of
the heavens (or the skies)