A.T. Robertson Commentary Matthew 14:13

"Now when Jesus heard [it], he withdrew from thence in a boat, to a desert place apart: and when the multitudes heard [thereof,] they followed him on foot from the cities." — Matthew 14:13 (ASV)

In a boat (εν πλοιω) "on foot" (πεζη, some MSS. πεζω). Contrast between the lake and the land route.