Albert Barnes Commentary Matthew 14:21

"And they that did eat were about five thousand men, besides women and children." — Matthew 14:21 (ASV)

Five thousand men, besides, etc. Probably the number might have been ten thousand. To feed so many was an act of great benevolence, and a stupendous miracle. The effect was such as might be expected. John says (John 6:14) that they were convinced by it that he was that prophet that should come into the world; that is, the Messiah.

See Barnes on Matthew 14:13.