also: ェ
particle
Directional particle indicating movement toward a destination or goal. Pronounced え in modern Japanese. Occasionally written as 江 in historical contexts.
学校へ行く。
I go to school.
彼は駅の方へ歩いた。
He walked towards the station.
The particle へ derives from the noun 辺 (へ), meaning 'vicinity' or 'direction'. The pronunciation shifted from へ to え in modern Japanese, but the kana spelling へ is retained.