Please help me understand 注がれた in this sentence and its conjugation


> 信じられないほど青い目、まるで淡いサファイアのようだ。その目がハリーを観察している。そして額の傷にじっと **注がれた** 。

Why did they use passive form in this sentence and what does it mean when
coming after noun + に ?




> **その目が** ハリーを観察している。そして額の傷にじっと **注がれた** 。

The subject for the 注がれた is (その)目.

「（～に）目/視線を注ぐ」 is a set phrase to mean "to watch/look/stare (at~)".

Here it's used in the passive voice: 「目が額の傷にじっと注がれた」, literally "The eyes were
focused intently on the scar on his forehead", i.e. "(The owner of the eyes)
stared/gazed at the scar on his(=Harry's) forehead."




> **その目が** ハリーを観察している。そして額の傷にじっと **注がれた** 。

The subject for the 注がれた is (その)目.

「（～に）目/視線を注ぐ」 is a set phrase to mean "to watch/look/stare (at~)".

Here it's used in the passive voice: 「目が額の傷にじっと注がれた」, literally "The eyes were
focused intently on the scar on his forehead", i.e. "(The owner of the eyes)
stared/gazed at the scar on his(=Harry's) forehead."

